In a recent interview with CinemaBlend (via Deadline ), The Fantastic Four: First Steps director Matt Shakman explained the reason behind the disconnect between his film and the Thunderbolts* post-credits scene. According to him, the Thunderbolts* scene was created quite late, when he was already working on the script of First Steps.

As it is, Shakman's film ends with the defeat of Galactus and life returning to normal for the Fantastic Four's universe — until the movie's Russo brothers-directed post-credits scene set several years later shows toddler Franklin being held by Doctor Doom.