Marvel Studios' Phase 4 is setting up several narrative opportunities that will allow them to easily introduce the X-Men and Fantastic Four in the the historic sale was finalized last year, meaning that Marvel Studios' Chief Creative Officer Kevin Feige and his team now have creative control over the X-Men and Fantastic Four.
It's only a matter of time before these Marvel characters debut in the MCU. So far, there's no official word about when and how they're going to be incorporated to the established franchise despite Feige laying out their whole Phase 4 blueprint with a mix of big and small screen offerings. He's also teased some projects with Black Panther 2 has its roll out locked. However, just because they are being purposefully quiet about their plans specifically for the mutants and Marvel's first family doesn't mean that they haven't started setting up their eventual arrival.
MCU's Phase 4 slate will feature the return of familiar faces and debut of new ones both in film and TV. None of them is explicitly confirmed to incorporate either X-Men and Fantastic Four characters into their narrative; however, some projects provide a narrative opening for Marvel Studios to introduce these heroes.
Falcon & Winter Soldier Has Rumored Wolverine Connections
Sam Wilson (Anthony Mackie) and Bucky Barnes (Sebastian Stan) reunite in Marvel Studios' first Disney+ series, John Walker/U.S. Agent (Russel Wyatt) will be introduced. The show already has a broad story to cover, but it also has some connections to Wolverine, making the show an easy MCU gateway for the mutants.
There are several clues from The Falcon and the Winter Soldier that imply a surprise Wolverine introduction. The flag of Weapon X program, which gave Wolverine his adamantium skeleton, and both are phases of "Weapon Plus." Given this, the exploration of Rebirth could lead to the discovery of Weapon X and its subjects including Wolverine.
Eternals' Changed Origins Leaves The Door Open For Mutants
Marvel Studios is set to introduce their newest superhero team in Chloe Zhao's Eternals. Boasting a star-studded cast, the titular characters are a group of of super-powered beings created by the Celestials who are essentially immortals. Their story will span thousands of years, although its main narrative is set after Avengers: Endgame. They're sent to Earth centuries ago to protect it from the Deviants, and by the time the film picks up, they've already been in the planet.
In print, the so-called "Space Gods" came to the planet and experimented on the DNA of primitive human beings. This resulted in two enhanced versions of the human species - the Eternals and the Deviants. Meanwhile, the X-Men are human subspecies born with superhuman abilities that were simply activated by the "X-Gene." The Eternals being extraterrestrials who were sent to the Earth by the Celestials avoids the obvious comparison in their origins with the mutants, allowing both of them to potentially co-exist in the MCU without occupying the same lane.
Phase 4 Movies & Disney+ Shows Are Opening The Multiverse
Avengers: Endgame teased the existence of the multiverse in the MCU. Though Mysterio (Jake Gyllenhaal) lied about it in Loki's escape with the Tesseract/Space Stone during Avengers: Endgame's Time Heist.
Once the multiverse is officially established in the MCU, Marvel Studios can utilize it as a way to bring in the X-Men and/or Fantastic Four. Mysterio floated the idea that he's an hero from a different dimension; though that is obviously false for him, it could be how the mutants come in to the primary MCU reality. Living in an entirely different dimension would explain their absence in the franchise thus far without having to start introducing them from scratch.
Dr. Doom Is Rumored For Black Panther 2
Technically a Phase 5 project, one of which is Doctor Doom. This comes from a report that the sequel will be loosely based on Marvel's Doomwar narrative where Doom gets entangled with Wakanda as he attempts to expand his empire in Africa.
Victor von Doom was the main villain in both of the Fantastic Four movie franchises, but like those films as a whole, the adaptation of the character fell flat. Given that, fans of Dr. Doom are still holding out hope that his next big screen appearance will finally capture the character's complexity. While he's primarily associated with Marvel's first family, Doom's supposed introduction in Black Panther 2 will immediately distinguish MCU's version of the character from its predecessors. Once he's established in the franchise, Marvel could set-up a match-up between Doom and the Fantastic Four moving forward. And the X-Men may not be far behind.