It appears that Fantastic Four is really a 20th Century Fox film ... but Disney's Marvel Entertainment had an association with the production.

I see films from several of the 6 MAJOR Studios on the 4K Studios Calendar ... Must be contracts in place in order for 4K Studios to be working on them ...

20th Century Fox ...
*** Fantastic Four
*** The Martian
*** Life of Pi
*** Ice Age: Collision Course

Columbia Pictures
*** Passengers

Walt Disney Studios Motion Pictures
*** Rogue One

Paramount Pictures ...
*** Indiana Jones and the Last Crusade ...
*** The Big Short ...
*** 13 Hours: The Secret Soldiers of Benghazi ...
*** Zoolander 2 ...
*** Whiskey Tango Foxtrot ...
*** 10 Cloverfield Lane ...
*** Everybody Wants Some !! ...
*** Florence Foster Jenkins ...
*** Ben-Hur ...
*** Jack Reacher: Never Go Back ...
*** Arrival ...
*** Allied ...
*** Fences ...
*** Silence ...

There's even a film from UA (Division of MGM) ... which is NOW considered to be a
Mini-MAJOR Studio ...

United Artists (Division of MGM) ... ...
*** Octopussy