During the Marvel Studios panel at San Diego Comic-Con, Marvel Studios President Kevin Feige revealed that the X-Men are coming to the MCU.
Kevin Feige was coy about the way he revealed the X-Men are coming to the MCU while still standing on the stage at San Diego Comic-Con, while he was willing to name-drop the Fantastic Four, he merely said “mutants” at the panel.
The X-Men finally becoming part of the MCU is being made possible by Disney’s $71 billion purchase of the majority of Fox’s media assets.
Since they purchased all of the movie studio 20th Century Fox, Disney acquired the rights to the X-Men and Fantastic Four.