See also the subpage for the theatrical films.
- Maketh Tua's death to some, due to being an Anti-Villain, making them a perfectly good candidate for future political plots from the Empire's perspective.
- Many people weren't impressed when Word of God confirmed that Wolffe and Gregor stayed behind on Seelos. Though given Wolffe's paranoia and Gregor's senility, they probably wouldn't have been much help anyway. This would be rectified in the Series Finale, where Wolffe and Gregor join Rex for the liberation of Lothal from Thrawn.
- Much like their predecessor, the Seventh Sister and Fifth Brother are killed at the end of the second season without much characterization or development, particularly the former who was a major fan favorite. The Eighth Brother also got this, as he was basically a Red Shirt.
- Many expected the Seventh Sister and the Fifth Brother to be on par with the Grand Inquisitor's prowess and competence, as well as having an active rivalry, due to Word of God stating that the entire Inquisition is fighting for the title of Grand Inquisitor. This doesn't continue past their debut episode. Characters in-universe as well as the audience end up treating them more like a joke and a nuisance than a huge threat by the end of the season.
- The Seventh Sister in particular is regarded to be a major waste of a character since many people were hoping that she would be Barriss Offee, a fallen Mirialan Jedi who has a history with Ahsoka Tano (being the Jedi traitor who ultimately led Ahsoka to leave the Jedi Order). Tellingly, there are many fan fictions depicting Barriss as Ahsoka's personal Inquisitor foe, while the Seventh Sister is only remembered for being a creep to Ezra in her debut episode.
- The Inquisitorius as a whole after the end of Season 2, which ends with every introduced Inquisitor dead, given Dave Filoni's statements indicating that the Inquisitors time on Rebels is up note (though it may be a case of Exact Words, as by "all the Inquisitors are dead," he could easily mean just the ones at Malachor). None of them besides the Grand Inquisitor are fleshed out (and most of the Grand Inquisitor's was done posthumously) and all have little screen time during their tenure.
- Henry Gilroy at Dragoncon 2016 had stated that the Inquisitors would return in the future and there is indeed a plan for a resolution, and also quietly suggested that they would reappear in the form of the Second and Fourth Inquisitors, so this story is not finished yet.
- At best, Kanan and Ahsoka have an amiable working relationship, but surprisingly they converse very little on their respective backstories which has some overlapping qualities, which included disillusionment with their own Jedi status, when you consider Kanan's backstory in the Marvel comics and A New Dawn. A more unexamined dynamic is that while Kanan reclaims his Jedi status, Ahsoka explicitly rejects it.
- The Leonis siblings' plot is dropped after Season 1 and never mentioned again, due to branching off into Servants of the Empire and concluding there. Most people were expecting Dhara to be introduced into the show as an Inquisitor, but the events of the books have eliminated that possibility.
- Despite being a main character and having a prominent role in the first half of the show, Zeb is Demoted to Comic Relief starting in Season 3, with the “Prophecy of Three” he was involved in never getting addressed past its introduction. Zeb also never directly interacts with Agent Kallus past the second season, which is particularly baffling given Zeb’s actions in "The Honorable Ones" was the impetus for Kallus’ Heel–Face Turn.
- Some believe that members of Phoenix Squadron should have become recurring major characters like how the clones did, so to prevent the Red Shirt trope. Not helped that various lookalikes cause subtle instigates to the plot (i.e. In "Wings of the Master," a generic green-suited pilot is Phoenix Leader and dies momentarily, then Hera gets promoted to his position at the end of the episode; "Homecoming" had a generic blue-suited female pilot get shot down right before a jump to hyperspace, making Hera and Sato realize that they need to find a way to substitute manpower when it runs short and to keep whatever they have left a safe place to dock; "Mystery of Chopper Base" had a literal Red Shirt be a concern when she fails to report back due to dying).
- Many wanted Kalani and his battle droids to join the Rebellion, but at the end of his episode, he instead chooses to go alone to parts unknown with only a few battle droids left accompanying him. Rebels Recon later suggested that he could become an hired adviser for people like the Hutts in the mean time or that he see that the Rebellion is a cause worth fighting for after the destruction of the first Death Star, so he could always come back later on in the show or in other material.
- People also wanted Sabine to design the battle droids, like how Jaybo from the Blue Shadow Virus arc from The Clone Wars did.
- A What Could Have Been idea was one of the battle droids joining the Rebellion, but it was scrapped because it would mean they would have to add Matthew Wood as a recurring cast member for an already growing ensemble of characters and voice actors (note AP-5's example above), so it seems like this is also in part to why Kalani did not join either.
- Gar Saxon. He surprisingly gets killed in his second appearance, but other viewers think that this was for the best, as it makes him a Disk-One Final Boss and prevents him from going through Villain Decay like other villains that some audience members are also getting on the negative end. However his brother Tiber Saxon in the two part season four premier 'Heroes of Mandalore', was so similar to his brother it made people wonder why they didn't allow him to escape and die in the second part of 'Heroes of Mandalore'.
- Ketsu is not brought up during Season 3 besides the Fridge Brilliance that she accidentally worsened Sabine's abandonment issues, but beyond that, we don't learn more about her role in Sabine's Dark and Troubled Past.
- Iron Squadron was not very well received due to having little characterization beyond being Expys of Ezra back in Season 1, who was also received as more of a scrappy back then. People who aren't as harsh think that Iron Squadron could've at least appeared more, as it would've also benefited Sato (who was also pushed more to the sidelines that season) due to Mart's familial ties with him.
- Of the several The Bus Came Back characters in "Zero Hour", Iron Squadron is surprisingly not at the Battle of Atollon, and have been absent for the entire season without explanation. Some agree their absence could at least been remedied throughout the season by cameos or namedrops to show that they were still actively working with Phoenix Squadron, and that Mart could have reacted to Sato's Heroic Sacrifice in the finale.
- Numerous ally characters from throughout Season 3 return in the season finale, but due to budget, many don't have beyond a couple of lines and don't do much beyond getting a couple of camera shots during fighting sequences.
- Some think that the other Clan Wren members should've been more developed beyond a Red Shirt Army so to actually give more gravitas to the situation for the audience while allowing Ursa and Tristan's survival to feel more acceptable.
- Ezra meeting Luke might've been an interesting way to set up a kind of Early-Bird Cameo, and perhaps even to lead into an appearance, or at least mention of, Ezra in the sequel series. Admittedly, he's only a small child, but it still might have given the fans some interesting characterization of Luke, and possibly Beru and Owen, prior to A New Hope. Filoni's stated reason for not involving Luke for more than a cameo was because he was afraid that some fans might not know who Luke Skywalker is. Yeah. Right. That makes sense.
- In the Grand Finale, Rukh gets killed without much insight into his character, making it feel like his entire presence on the show was to be a Red Herring toward how Thrawn would be defeated.
