20th Century Fox currently owns the rights to both the X-Men and Fantastic Four franchises, but according to comic book legend Stan Lee, Marvel is currently trying to regain the rights. Lee revealed at Wizard World Nashville that “they’re working on” getting “the rights back”:
“Sooner or later, they’re going to get the rights back to all our characters. They’re working on it, and they’re still making X-Men movies and stuff. Don’t worry about it. You’ll get more Marvel superheroes than you’ll have time to look at in the next few years.”
Although Lee has a powerful reputation, he actually has no involvement in Marvel’s day to day operations so we can’t take his words too literally. Especially as Marvel Studios President Kevin Feige said it was unlikely those films would enter the MCU.
20th Century Fox recently set dates for six more Marvel films up to 2021, including Deadpool 2 and X-Men: Dark Phoenix. While next up in the MCU is Avengers: Infinity War, which opens on May 4, 2018.