10. Doctor Strange 2 May Include Alternate Versions Of Familiar Faces
Doctor Strange revealed the existence of a Multiverse and Avengers: Endgame doubled down on that by exploring alternate timelines and explaining what sort of ramifications one minor change to them could result in (the Loki TV series, for example, will explore a timeline where the God of Mischief never died and remained a villain).
According to MCU Cosmic, though, Doctor Strange in the Multiverse of Madness will introduce, "some known MCU characters but in very different ways." In other words, that means we could end up visiting other worlds where familiar heroes and villains turned out very differently.
With that in mind, the reason for that animated What If? series is starting to become clear as it gives Marvel Studios the chance to explore some of those worlds, minus the big budget a live-action version would demand.
Oh, and with Spider-Man director Sam Raimi now in talks to direct the Doctor Strange sequel, don't be surprised if this leads to Tobey Maguire reprising the role of the web-slinger for a brief cameo appearance! This could even be used to explain the introduction of characters like the X-Men and Fantastic Four.