Doctor Strange In The Multiverse Of Madness writer also wanted to see Tom Cruise show up as Iron Man
At least one dream MCU cameo did come true, so there's no need to be greedy anyway
[The following contains spoilers for Doctor Strange In The Multiverse Of Madness, but most of them are about a version of the movie that does not exist in this reality.]
Ever since officially unleashing the multiverse in Loki, the Marvel Cinematic Universe has largely used it as an excuse for payoffs and fan-service. That was basically the whole premise of What If…?, with its alternate versions of heroes and ultimate mega-villain (Ultron with the Infinity Stones), and it helped bring untold mountains of cash to Sony and Marvel by allowing for three different Spider-Mans to meet up in Spider-Man: No Way Home. So it was obvious that Doctor Strange In The Multiverse Of Madness would feature some No Way Home-esque Easter eggs even before that Super Bowl teaser first hinted that Professor X might be making an appearance.
With Professor X seemingly confirmed, all bets were off: Would Eric Bana’s Hulk be there? Would we get a nod to years of dream-casting John Krasinski and Emily Blunt as Reed Richards and Sue Storm? Would the Tom Cruise version of Iron Man from the “If they made The Avengers in the ‘90s” meme show up?
Well, one of those actually happened, and it’s not Tom Cruise’s Iron Man, but Multiverse Of Madness screenwriter Michael Waldron recently told Rolling Stone that he would’ve loved to get Tom Cruise in the movie. He says Cruise was never formally approached and no footage of Cruise as Iron Man in this movie exists (despite some supposed leaks going around), but it was part of his initial plan at some point. He says he wanted to do it simply because “Tom Cruise as Iron Man” has been floating in the digital ether for decades and he thought it would be fun, but he doesn’t think anyone even reached out to Tom Cruise because of the many Mission: Impossible movies he’s making in Europe.
The rest of the Rolling Stone interview doesn’t have any other what-might-have-been teases, but it does offer some interesting insight on Waldron’s writing process for the movie (including the revelation that a confusing Fantastic Four joke was an ad-lib from Benedict Cumberbatch and is not meant to be confusing).