The sequel to 2015's Fant4stic was supposed to be released on June 9, but, quite understandably, Fantastic Four 2 never entered production. An interviewer with AlloCiné asked Kevin Feige whether Marvel intended to make a deal with 20th Century Fox that would be similar to their Spider-Man deal with Sony .
Since it became clear that Marvel and Disney know what they’re doing, fans have wanted to see Marvel's First Family join the Marvel Cinematic Universe. And we’re not just talking about casual fans.
Director Scott Derrickson (Doctor Strange) said that he hoped to see Mister Fantastic, Invisible Woman, Human Torch, and Thing as Avengers. In addition, James Gunn, whose decision-making powers have increased since Guardians of the Galaxy: Vol. 2, said that he'd like to have one Fantastic Four-related villain in one of his movies (none other than Annihilus).
Feige has teased the Illuminati on several occasions, with Mr. Fantastic as a founding member, so we can understand why everyone is asking about the Fantastic Four in the MCU.
Unfortunately, the Marvel boss reiterated that there have been no discussions with Fox in regard to these characters:
[We have] no plans with the Fantastic Four right now. No discussions about it (via Newsarama).
Of course, we could say that Feige doesn't discuss characters affiliated with the team (such as Annihilus). We could also say that the title for Avengers 4 hasn't been announced because a secret deal is in the works. But that would be quite a reach.
We'll just say that 20th Century Fox has five years to come up with a Fantastic Four movie before the rights to the characters revert to Marvel.