Recent history has shown that the Fantastic Four are pretty much box office poison. The first attempt at an FF movie in 1994 was so bad it was permanently shelved.
The two big-budget attempts in the early 00s may not have crashed and burned, but they didn't become smash hits either.
The 2015 reboot was a disaster on every level.
Therefore I'd be surprised if they got another shot at the silver screen anytime soon, at any studio.