May have been accidental, but during Mark Millar's arcs, there is one where The Invisible Woman, along with a lot of other super heroes from the year 25xx, goes back in time to bring their civilians into the old Earth. To do this, they have to use Galactus as a battery. The fight brings the number of living heroes from hundreds to six. The Invisible Woman remarks that her 'Husband and children died to get there.' It was strange when she didn't mention Johnny, who was standing right there. Then I realized that was because, since they were from the future, Johnny was already dead. It was foreshadowing his death a good twenty issues before the it ever happened.
Probably just a coincidence, since Johnny returned from the dead 12 issues after he died in the first place.
In an issue of Mark Waid and Mike Wierango's run, the Fantastic Four basically meet God — who turns out to be a comic book artist with an unseen collaborator who bears a striking resemblance to Jack Kirby. Which is not only a perfect tribute, but makes complete sense on a metaphysical level; who else would a comic book superhero view as God but the artist / writer who created them and the world they live in?
I always used to think Mister Fantastic was a dumb superhero name, mainly because it's so non-descriptive of his powers. Then it hit me; this comic came out in the era that gave us the expression "Plastic Fantastic". So, it's basically a somewhat subtle way of saying "Yeah, he's basically our answer to Plastic Man." —Cuchulainn
Reed Richards Is Useless actually makes sense considering that most of the comics came out during the Cold War - in fact, if we apply comic book time to the Marvel Universe from the Fantastic Four's debut onwards, they're STILL in the Cold War. So let's say that Reed decides to release the Universal Translator to the public, or to the military? Suddenly, it becomes much easier to translate Soviet communications. What if the USSR replicates this technology? Then both sides of a nuclear standoff can spy on each other without needing a translator - and the same technology could be repurposed to hack any computer. How long until a nuclear war breaks out in that situation?
Say what you want about the Galacta issues, it explains why Galactus' hunger grew over the centuries since the big bang; he was pregnant himself.
Galactus No Selling Darkseid's Omega Beams makes perfect if you realize he's been beyond the Source Wall (and came from a time before the Big Bang.)
Doom's face is hideously scarred because of an experiment that literally blew up in his face back in college. The experiment itself was a machine to let Doom contact hell, and it's often explained that Doom, due to his outrageous arrogance, ignored a flaw in the design which Reed pointed out to him, and it was this flaw that led to the machine's failure. However... Doom is an incredibly smart man, always has been and always will be. Yes, he's arrogant to the point of stupidity, constantly shooting himself in the foot through the sheer size of his ego, but even he is smart enough to notice a blatant design flaw. So what if the machine actually worked? It's revealed in a later story that Doom's mother is trapped in Hell, full of fire and brimstone. And what happened when Doom activated his machine? He got blasted in the face by a cloud of searing flames. What if the machine, that we've all thought for years malfunctioned, actually worked perfectly...?
The Maker is trying to restore the Ultimate Marvel universe in Venom (Donny Cates) and Ghost Spider, but Spider-Men II had shown that it returned, and even the 616 Miles Morales returned from it in Miles Morales: Spider-Man (2018) along with Ultimate Green Goblin. A mistake? The Maker did not realize this? Perhaps it's not the case. The scenes in Spider-Men never mentioned which earth was that, and some details in it don't make sense (Riri in the Ultimates, Captain America and Giant Man alive again, Thor is back and still has his hammer, etc.). Perhaps it was not really the Ultimate Marvel universe but just a close alternate replica, similar in everything except some details (the 616 universe has its own almost similar alternate versions, after all). And the Maker is not someone who would settle for the Closest Thing We Got!
The early comics have a lot of this, due both to Values Dissonance and just bad writing. For example, the treatment of the Skrull agents in #2. Instead of imprisoning or executing them, Reed literally turned them into cows. This was (and still is, much of the time) treated as funny for the absurdity of it, but is actually really horrible if you stop to think about it. Imagine if that had been done to a human villain...
In Annihilation, it is revealed by Thanos that the Power Cosmic displaces and destroys the soul of Galactus's Heralds. No afterlife for them.
