What if we told you Kevin Feige has single-handedly changed what is and what is not officially canon in the MCU. You’d probably say, “yeah, that tracks,” or maybe “surely not EVERYTHING pre-Iron Man is canon.” Well, that’s where we’d have to stop you and direct your attention to “Marvel Studios: The Marvel Cinematic Universe—An Official Timeline” book.
President of Marvel Studios Feige wrote the intro for the book. He snuck in a little tidbit about the Sacred Timeline, and what actually counts as canon now.

Ok, so, obviously this can be taken a few different ways. But, the obvious thing to take away there is other Marvel projects not produced or under the Marvel Studios banner count. Either now or eventually, especially following the FOX/Disney merger, which brought long-lost children the X-Men, Fantastic Four, and other characters home. (Yeah, Sony still has all the Spider-people, hence “Kraven,” “Madame Webb,” and “Venom.”)
We already saw some of this; Charlie Cox‘s Matt Murdock/Daredevil appearing in “She-Hulk,” Vincent D’Onofrio‘s Wilson Fisk/Kingpin in “Hawkeye.” But the possibilities moving forward past Phase 4 are endless.
What’s really interesting here is what this means for some of the forgotten projects, like Roger Corman‘s “Fantastic Four.” If you’ve never seen “Doomed: The Untold Story of Roger Corman’s The Fantastic Four,” you absolutely should. It details the unfinished film that may or may not now officially be part of the MCU.
The next project releasing will be “Echo,” which hits Disney+ January 9th, 2024.