Hilarious In Hindsight / What If?

• If only one of them wasn't spoileriffic as hell, these three "Homage Covers" would be the perfect image for this page because they all are canon now.
• The very first issue of What If...? asked "What If Spider-Man had joined the Fantastic Four?"; since then, this has actually happened not once, but twice in 616 continuity - Spidey was a member of the short-lived New Fantastic Four, and later a member of the proper team in place of his then-dead friend Johnny Storm.
• What If...? #30's premise was "What If Spider-Man's Clone had not died?", based on a then-recent story arc. Then in the 90s, the idea was revisited in earnest in the infamous The Clone Saga.
• Issue #58 of the second run of What If?, released in 1994, asked the question of what would have happened if the Punisher had killed Spider-Man. One splash page of the issue shows a montage of big name Marvel superheroes with ties to Spider-Man beating the crap out of the Punisher. This was released only one year before Garth Ennis's The Punisher Kills the Marvel Universe.
  • Similarly, issue #51 of volume 2 was "What If the Punisher became Captain America?", which later became an actual Punisher: War Journal storyline in 2007. Granted, he was never officially Cap, but this was before Bucky Barnes stepped into the role, meaning he was effectively the closest thing to the real deal out there.
• Speaking of Bucky, there's an issue of the first volume ("What If Captain America & Bucky had not disappeared at the end of World War II") where at one point, he takes up the Captain America mantle to replace an aging Steve Rogers. That's right, Bucky was Cap a good 31 years before he takes up the identity in the main Marvel Universe. In that same issue, Steve replaces Bucky as director of S.H.I.E.L.D., which also happened later in the main canon - and both times were after Bucky became Cap.
• An issue of The Invaders from the 70's had a scene where Bucky makes a joke about going through an identity crisis. This was years before readers found out he'd been Brainwashed and transformed into a murderous Soviet assassin.
• Issue #9 of the second volume asked "What If the New X-Men had died on their very first mission?" X-Men: Deadly Genesis would reveal that this is exactly what actually happened, because Professor X had gathered a new team to save the originals from Krakoa before the more familiar "All-New, All-Different" guys.
• Issue #16 of the same volume, "What if Kraven the Hunter had killed Spider-Man", features Kraven, a villain obsessed with defeating Spider-Man, taking up his costume and becoming a darker version of him. His dialogue as he makes this decision is... familiar.

  Kraven: I will hunt as the Spider hunts - and all will see that I am his superior!

• The Agents of Atlas would count, in the sense that it's another "What If...?" that became more of a "How About...?", except in the story, Iron Man explicitly brings up the possibility of that team of Avengers existing in their reality as well as a plot hook for future writers, which was what the team behind Agents of Atlas picked up on. So it's not Hilarious in Hindsight so much as it is a "How Come It Took You Guys So Long" Moment.
• Conan the Barbarian, when he was a part of the Marvel Universe, had not one, but two What Ifs exploring the idea of him popping up in modern times, with the second one ending with Conan considering the idea of joining the Avengers. Wait, did we say was part of the Marvel Universe? Sorry, we meant IS - because not only is Conan back with Marvel, not only is he in modern times, but he just so happens to have joined the Savage Avengers!
  • In the first part of the latter story, a woman briefly mistook him for Arnold Schwarzenegger, the actor who would end up playing the character in Conan the Barbarian (1982) several years later. Another bystander confused him for Sylvester Stallone instead - both were popular speculation for people who could play Conan at the time.
• Much like the Geoff Johns example in the DC section, "What If?" Issue #32 featured a letter page full of What If ideas from fans, some examples being "What if Cyclops had gained the power of the phoenix?", "What if Dazzler joined the X-Men?", "What if Mary Jane had accepted Peter Parker's marriage proposal?", "What if Magneto had formed the new X-Men to battle the old?" and "What if Toro had not died in Sub-Mariner #14?", all of which came true in some way, shape or form.
• The "Sgt. Fury fighting World War 2 in outer space" issue seems like a Bizarro Episode at first, but now considering the Retcon in Original Sin that Nick Fury had a secret job of safeguarding the Earth from alien threats the whole time, the notion of Fury battling in space doesn't seem so silly.
• In What If? Special, the divergence point is that Iron Man was secretly a double agent working for the commies, albeit against his will. This is either Hilarious in Hindsight or Harsher in Hindsight given what happened in The Crossing (where Tony was revealed to secretly be working for Kang the entire time). The impact is lessened now that Avengers Forever retconned it so that he wasn't being controlled his entire career, at least, but he was still a double agent and still turned on the Avengers like he did in this story.
• More examples of What Ifs somehow influencing canon: Flash Thompson becoming Spider-Man happened in three issues, and he's now Agent Venom and Agent Anti-Venom. In the first time that happened, another story had Betty Brant became Spider-Woman, prefiguring another alternate version of a girlfriend of Spider-Man, and yet another had Jameson's son get the powers (he never became a Spider-Person but did end up getting powers as Man-Wolf). Issue #2 of the original series had "What if the Hulk retained Bruce Banner's personality", which is practically self-explanatory now that it happened so many times, most famously with the Professor Hulk. Another issue had Rick Jones becoming the Hulk, which would be revisited with Hulk Jones and A-Bomb. Issue #22 had Dr. Doom becoming a hero (Infamous Iron Man). Issue #35 had "What if Elektra had lived" (she came back, obviously). The first issue of the 1989 volume has the All-New, All-Different X-Men perishing in Krakoa trying to save the originals (it would later be retconned that Xavier's second team did die on Krakoa). Others were "What if the Fantastic Four's second child had lived" (she did, with some help from Doctor Doom), "What if the Age of Apocalypse had not ended" (it didn't), "What if J. Jonah Jameson adopted Spider-Man" (he adopted Spider-Girl instead!), and there are likely still others, as well.
• There was a "What If?" in the second run where Iron Man became Sorcerer Supreme. In Infamous Iron Man, Bendis tried to imply that in the future, he would, but then it ended up going nowhere, as he left the book (and Marvel) shortly afterwards.