In his long interview with Variety, Kevin Feige addressed the MCU changing its release strategy in Phases Four and Five. After Endgame we were treated to a ton of content, both in theaters and on Disney+. The Marvel boss spoke about what happened, saying:

Kevin Feig e recently discussed Marvel Studios’ approach to The Fantastic Four: First Steps and its Earth-828 setting in a new press interview. He explained the early decision to set the film in a separate universe, the goal of making it accessible to new viewers, and how Disney+ overexposure influenced the studio’s direction.