Not going to link the original TLP here as this is a categorization issue.

The problem: I Knew It! is about when a fan theory is later proven to be true. Despite clearly being an opinion-based Audience Reaction (since a fan theory would IMO clearly qualify as one) I Knew It! is listed as Trivia. mightymewtron mentioned this in Trope Talk, and I decided to do a wick check since I was pretty shocked this wasn't YMMV myself.

Wick check: Link here, but here's the quick results:

• 32/50 wicks were written in a way that focused on the audience reaction, or 64%
• 3/50 wicks were written in a way that did not focus on the audience reaction, or 6%
• 7/50 examples were misuse, or 14%, and
• 8/50 examples lacked context or were unclear, or 16%

Analysis: As expected, the vast majority of wicks were written in a way that emphasized the reaction of the fans, or rather the audience. Very few entries were written like Trivia, and while there was some misuse for non-fan theories and zero-context examples, IMO it wasn't enough to justify a rename.

Possible solution: I propose moving I Knew It! to YMMV (and specifically Audience Reactions) based on all of this.

What does everyone else think? Any other ideas or suggestions?

1. Recap.Power Rangers Dino Charge Worgworld: Wham Shot: Crosses into Foregone Conclusion territory since so many people guessed it, but Sledge's reappearance is a major game-changer. Pothole references the audience reaction specifically.
2. Trivia.Argonavis: The minute he debuted in the manga, many fans correctly theorized that Koga Iryuu was Nayuta's father. References the audience reaction specifically.
3. Trivia.Blink 182:
   • After spending months prancing about how awesome he was, Mark and Travis finally confirmed Matt Skiba is a part of blink-182, to the annoyance of a subset of fans.
   • In 2022, during an impromptu tour with Alkaline Trio, his main band, Matt Skiba in an interview questioned his status in blink-182, leading to fans speculating that Tom is returning. It was later confirmed in early October of that year that Tom is back. References audience reactions specifically.
4. Trivia.Brimstone Valley Mall: A good chunk of the audience had guessed that Trent is an angel before the tenth episode confirmed it. Reference to audience reaction specifically.
5. Trivia.Didnapper 2: Many theorized that Alyssa and Dariana would make an appearance in this game due to how their story ended in the first game and the fact that from the beginning they knew that there would be pirates among the antagonists. It was eventually confirmed by the character artist by posting her Battle Art in DeviantArt. Reference to fan theory specifically.
6. Trivia.Duck Tales 2017 S 2 E 21 Timephoon: Some viewers suspected this would be the episode where Della would learn how to discipline her child, with said child being Louie. References audience reaction specifically.
7. Trivia.Havenfall Is For Lovers:
   • Fans speculated from almost the beginning that the heroine has some kind of supernatural nature, citing her ability to pack-bond with Mackenzie in the latter's route and her resistance to supernatural influences such as JD's memory-tampering. Antonio's first season confirms the theory via Antonio and Igor both seeking to make use of her "special" qualities, though their origin and exact nature (and whether or not the plot point remains consistent across all routes) has yet to be revealed.
   • The fans also popularly assumed that Antonio is bisexual based on his interactions with Diego in Diego's route. This was confirmed via Antonio's inclusion on Lovestruck's official list of LGBTQ characters shortly before his route launched in June 2018.
   • There had been a lot of speculation starting early on that Luce is evil and/or more than she seems, which was also increasingly hinted at in-game. In Razi's fifth season, she's revealed to be Baba Yaga. References to audience reactions specifically.
8. Trivia.Hi Fi Rush:
   • Even by the trailer alone, lots of players have already guessed that Korsica will pull off a Heel–Face Turn, or at least being a Token Good Teammate just from her distinct design.
   • Two moments in Track 2 — Peppermint getting mad that Chai doesn't know who Roxanne Vandelay is, and later when Kale is suggested to be familiar with Peppermint — made players immediately suspect that Peppermint is secretly a Vandelay as well. Granted, many players suspected that Kale was her father due to how much older he looks, further reinforced by the museum claiming Kale is an only child, only for it to be revealed later that Peppermint is his sister and he scrubbed her from Vandelay's history. References to audience reactions specifically.
9. Trivia.Dragon Ball Super Galactic Patrol Prisoner Arc:
   • As stated by Geekdom101, many people were correct in their guess about Merus's identity being that of an angel months before chapter 55. Geekdom himself made a video titled Merus the Angel in October 2019, two months before the chapter was released.
   • Likewise, Geekdom101 predicted Moro wouldn't be able to absorb the Androids' energy as they don't generate Ki in Who beats Moro in Dragon Ball Super?, published in March 2019. References to audience reactions.
10. Trivia.Batman Arkham Knight:
    • Several people correctly speculated that the plot of Arkham Knight would involve a power-vacuum after the death of the Joker, based solely on the ending to Arkham City and that Scarecrow would be the Big Bad based on his hidden room in Falcone Shipping.
    • Regarding the Joker, two sets of theories came up regarding his fate. One set of fans believed that the character was completely dead and would be exempt from Joker Immunity or being resurrected somehow, and the other set of fans believed the same, but were under the impression that the character would be seen in hallucinations and flashbacks. Both groups were correct.
    • A lot of people correctly predicted that the Arkham Knight's true identity was the Arkham-verse's version of Jason Todd.
    • It was also widely speculated that the climax would happen at Arkham Asylum.
    • Many people figured out that it was John Noble who voiced Scarecrow before the official reveal. References to audience reactions.
11. Headscratchers.Metroid: That explanation's from the Bob and George fancomic Metroid: Third Derivative, which is decidedly Fanon, even if the author did get a surprising amount of things right about Prime 3. Seems to be referring to an audience reaction.
12. Music.Hyadain (in description): He eventually revealed on his blog that he is in fact Kenichi Maeyamada, a professional composer in the Japanese music industry, which was suspected by a good many of us due to the incredible quality of his work. Pothole refers to audience reaction.
13. Trivia.Avataro Sentai Donbrothers:
    • Many viewers guessed correctly that Tsuyoshi/Kiji Brother would become a Hitotsu-Ki after he caused the death of Mashin-Ki.
    • Similarly, viewers' guesses that part of Toshiki Inoue's Signature Style involving a Love Triangle would be included in the series would be confirmed in #34.
    • Several viewers were correct in their theory that Naoki Shiina is actually another version of Haruka.
    • Quite a few fans guessed correctly that Minoru Ohno would be the host for Ohsama-Ki. References to audience reactions.
14. Trivia.Ed Edd N Eddys Big Picture Show: Quite a few fans predicted that not only would Eddy's older brother appear in the movie, but that he would end up being the movie's Big Bad (or, since he's revealed to be the reason behind Eddy's bad behavior, making him the Greater-Scope Villain). Focus on audience reaction.
15. Trivia.Game Of Thrones S 8 E 3 The Long Night:
    • Theon and Jorah were two of the most popular choices among the episode's major casualties. Though it was intended for quite a while that Jorah would survive.
    • The Night King raising the corpses buried in the crypt had been called by a lot of fans since the previous episode. Focus on audience reactions.
16. Trivia.Justice League Vs The Fatal Five: After years of speculation on who Batman considered to be among the three smartest men in the world in the DCAU (two of them were on the Watchtower, and the first smartest man is Lex Luthor), Word of God on the behind-the-scenes featurette packed with the Reign of the Supermen DVD confirms the popular theory (supported by a tagline from the character's comic) that Mr. Terrific is the third smartest man on Earth and the smartest man in the Justice League. Focus on audience reaction (being proven true).
17. Trivia.Parallel Paradise: Ever since Chapter 50, readers had speculated on the possibility that the God of Deep Jealousy would turn out to be Nishina. Then Chapter 80 came around... The exact circumstances of it, though... nobody saw THAT coming... Focus on audience reaction.
18. Trivia.PAW Patrol: Due to the ending of PAW Patrol: The Movie and a International Women's Day post on Nick Jr.'s social media showing her, some fans guessed that Liberty would appear in the series proper before a promo confirmed this. Focus on audience reaction.
19. Trivia.R Type: The demo for Final II features a frozen Dobkeratops as the first stage's boss, with its chest doing all the attacking. The last trailer before the game's release features an unfrozen Dobkeratops in action, confirming fan speculation that there will be another form for Dobkeratops that can only be fought on higher difficulties (note that the demo allows the first stage to be played in difficulties up to Bydo instead of R-Typer). Based on audience reaction.
20. Trivia.Star Wars Resistance:
    • After the announcement of Rebels, rumors went out that the series following Rebels would be titled Resistance. Whether or not those rumors were true or just lucky (considering that Resistance is a fairly obvious title choice given some of the other Star Wars titles) remains uncertain.
    • That based on the way he acts, Captain Doza was a former Imperial officer.
    • After "The First Order Occupation" introduced the underwater sections of the Colossus and concept art showed that the Colossus as a whole is similar in shape to Skystrike Academy, many accurately predicted that the Colossus was actually a space station or spaceship, which was confirmed in "No Escape, Part I". Based on audience reactions.
21. Trivia.The Caligula Effect 2: Many fans had a theory about Marie Amabuki and Wicked from the first game being the same person is due to them having the same voice actors, first names and similar appearances. This is confirmed in both the Bad Ending, where Marie regains her memories and former identity as Wicked, and in her Character Episode where she remembers her past self's actions in the real world and in Mobius. Based on audience reaction.
22. Trivia.The Flash Infinite Frontier:
    • Some fans were calling the reveal that Wally didn't cause the Speed Force explosion at Sanctuary after the first issue, given how easily it explains what happened, which didn't even make sense within the story it was being told in. That and how many people dislike Heroes in Crisis.
    • Linda's powers being due to pregnancy. It was the most common fan theory on social media as to where the powers came from, especially as genre works have often done similar plots, so when the second annual ends with a heavily hinted realisation of the source of the powers, few were surprised. Based on audience reaction.
23. Trivia.Thunder Cats 2011:
    • The death of Lion-O's mother in childbirth was one of the major fan theories from the very beginning.
    • Several fans settled on the name "Leona" for the Queen of Thundera before Dan Norton confirmed they crew called her that too.
    • Almost immediately after Panthro lost his arms fans not only theorized that he would get new cybernetic ones, but it's the Berbils that hook him up with them. Guess what happened in the very next episode.
    • A few fans actually did guess that Pumyra would betray the Cats a week before it happened. Based on audience reactions.
24. YMMV.Kirby And The Forgotten Land (under Epileptic Trees): The butterfly that was involved with Morpho Knight in Star Allies is shown again in the intro here, making people theorize that it's going to be connected with the plot somehow. Sure enough, Morpho Knight reappears as an extra boss. Based on audience reaction.
25. YMMV.Hamatora: Everyone called Art having an Immortality Minimum back when the first season was still airing. Then it was confirmed in the second episode of Re:Hamatora. Based on audience reaction, listed as YMMV to boot.
26. WMG.Metal Gear: Kojima pitched the idea after MGS4, but didn't feel that the team was experienced enough to make the game without his involvement. Hopefully, we can say that we called it one day. Seems to be based on an audience reaction.
27. Trivia.Mortal Kombat X: In part 5 of their MKX Let's Play, Pat from Two Best Friends Play admits that his fantasy is that the story mode ends with Liu Kang and Kitana replacing Shinnok as the rulers of the Netherrealm. Guess how the story mode ends? An audience reaction, since Two Best Friends Play are technically the audience.
28. WebVideo.History Of Power Rangers: Awesomeness Is Volatile: Linkara's theory for why the Rangers give off sparks when they hit something and why there are explosions behind them after they morph during the team-ups—there's just so much energy being given off. invokedThis has actually become more or less the canon explanation Dr. K gives for the giant explosions that occur behind the Rangers in Power Rangers RPM. An audience reaction, since Linkara is technically the audience.
29. Webcomic.The Cyantian Chronicles: A recent character addition to Akaelae, Brynn, has me wondering if her name is only a coincidence or if it's deliberately similar to Brunhilde / Brynhild. This is both spoilerriffic if I'm right and an I Knew It! moment. Or just another wild mass guess. Refers (judging by the first-person writing) to an audience reaction.
30. Headscratchers.Resident Evil: Six years ago, I had a case of I Knew It! while discussing the issue with a fellow player. I accurately predicted that Wesker's super virus wasn't perfect and required some special stuff just to keep it up and running. It is a major plot point of the final chapter of RE5, and Wesker's one and only weakness. That probably also what made this virus useless for a Super-Soldier program like the one Irving was working on. Imagine that Wesker's body needs something that probably costs more than 200000 bucks per shot and need one shot per 24 hours just to keep running correctly. Pothole refers to an audience reaction.
31. Trivia.Wayward Guide For The Untrained Eye:
    • Fans who guessed that the werewolves were in the anti-mining camp and being framed for the murders, or that Paul had been turned into one.
    • Fans who guessed Sybilus, Olivia, Rita, Vern, or Helen were werewolves.
    • Fans who guessed Truman was either behind the murders, a supernatural creature herself, or descended from the McMahon family.
    • Anyone who suspected Desmond was a werewolf, particularly of being "Connor" from Episode 5. Based on audience reactions.
32. Trivia.Yu Gi Oh Duel Links: Many players predicted a GX world would be added down the line, as well as a 5D’s world. And, as of September 2020; Zexal world has been added, too. Based on audience reaction.

1. Trivia.Caillou: While it was a bit obvious, Andy (from season five's "Follow Me") was officially confirmed to have autism in "Caillou and the Fire Alarm" from New Adventures. No reference to audience.
2. Trivia.Dying To Be A Cheerleader: The identity of the murderer is very blatantly obvious by the halfway point, but the movie insists on dragging out The Reveal to almost the last possible moment. No reference to audience.
3. Trivia.Underverse: Ink's special vial containing the other half of XGaster's soul was something long speculated given X-Event!Chara's fixation on it and the frames of XGaster showing up in the original 3.0 Part 1 and 3.0 Part 2. Page 85 of the X-Tale prequel comic confirms this. Written in a way that doesn't really mention the audience.

1. Funny.Gunnerkrigg Court: Reynard's reaction when Kat mentions offhandedly that she was kissing her girlfriend. He turns around as if to say I Knew It!; only for Kat to stop him by stomping on his face. Not a fan theory.
2. LetsPlay.Super Jeenius: Joke and Receive: In his Danganronpa Trigger Happy Havoc LP, he manages to correctly guess that Hifumi would be murdered by Celeste while he was making a joke. Not a fan theory.
3. Recap.Freakazoid Season 2 Episode 2: In-universe and Played for Laughs. After Freakazoid tears up the Superhero Code Book in frustration, a lone scrap keeps floating back in his direction. When he finally reads what it says and realizes that The Lobe played him, he has this reaction, only for a subtitle to say otherwise.
   Freakazoid: I KNEW IT!
   NO HE DIDN’T Not a fan theory.
4. Recap.Victorious S 4 E 6: Jade insists she always knew there was something going on between Beck and Meredith.
   Jade: I knew it! I knew it two years ago when you were in that awful play with her!
   Andre: I think I wrote that play. Not a fan theory.
5. Trivia.Penn And Teller Bullshit: A really dark example. Penn has told of his original pitch to the executives, which came 2 weeks after 9/11. As a part of it, he said that although he himself wasn't psychic, he could reasonably predict that within 6 months, psychic John Edward would announce a broadcast where he would channel the spirits of those who died in 9/11. In fact, it only took 3 months for Edward to do that, and the execs were impressed enough to greenlight the show. Not a fan theory.
6. Webcomic.Unsounded: I'm Standing Right Here: When Duane's nature is revealed to Toma and Quigley, they immediately disregard the pressing threat in order to engage in I Knew It! with each other and theorize that he's a mindless plod under someone else's control while Duane is standing right there. Eventually he gets fed up and uses pymary to knock their heads together. invoked
   Quigley: ...This makes sense. No legitimate human could be such a prancing twat-\ This and the other pothole on the page are not fan theories.
7. YMMV.Inspector Lynley: Clever viewers may find themselves shouting this, especially since whodunnit is often not who you'd expect and therefore being right is all the more exciting. Not really fan theories, general example at any rate.

1. Awesome.Marble Hornets: Entry #35: Jay and Alex are ambushed by the Masked Man. They fight him off, pin him on the ground, tie him up and unmask him (to find out that it's Tim). No context pothole.
2. DragonAgeInquisition.Tropes A To E: "Well, shit." This is very much the Inquisitor's thing, invoking this at the end of Solas' and Vivienne's personal quests as well as discovering that Nightmare is nearby. Varric's personal quest is titled such, and in the Descent DLC, he echoes such sentiments on finding the Nug King. No context pothole.
3. NightmareFuel.Dragon Age Inquisition: You can find a Codex entry in Valammar called "A Different Darkspawn?", which tells the story of a group of Dwarven smugglers trying to find the guy who has the keys to their cache. When they do find him, instead of him being dead, he apparently was found and cared for by a talking darkspawn like Corypheus or The Architect. The guy writing the note remembers a story passed down from his grandfather's grandfather about three talking darkspawn, dressed like kings and arguing with each other about "a city gone black". They ended up fighting each other and one ran while the second ate the third one. Give this a little thought: Not only did three other darkspawn magisters like Corypheus survive, but, assuming they are capable of killing each other, there could be another two running around the Deep Roads somewhere and, assuming the legends that there were seven are true, another three entirely unaccounted for. Even worse, if the In-Universe speculation of an eighth old god is true, there could be a corresponding eighth magister. Last but not least, Word of God confirms that the player has already met one of the other magisters. Low context pothole.
4. Trivia.Community:
   • Jeff returning to Greendale as a teacher in Season 5.
   • Pierce suffering from a Bus Crash after Chevy Chase left the show.
   • Troy being given Pierce's fortune and it being his reason for leaving Greendale. No context on all three.
5. Recap.Film Reroll Hocus Pocus: Outdated by Canon: The theory that the Sanderson sisters aren’t biologically related was disproven by Hocus Pocus 2, which premiered before the campaign was released, but after the latter was recorded.^note  The original concept for the characters was that they were half sisters, though neither of the above works take this as canon. On the other hand, the idea that they had been inducted by an older coven leader turned out to be entirely accurate. Pothole unclear on if it's a fan theory.
6. VideoGame.Tales Of Hetalia Late-Arrival Spoiler: The Allies and Axis are the Judges. No context pothole.
7. WMG.Fire Emblem Heroes Future Character Predictions: Sothis confirmed! She becomes the second Dark mythic. No context pothole.
8. WMG.Adventure Time: Holy crap, you hit the nail on the head. No context.