This film is ultimately a story that’s responsible for introducing us to heroes like The Flash (Ezra Miller) and Aquaman (Jason Momoa), not to mention a Green Lantern, so removing a character like Perry adds room for them to receive more attention.
It’s admittedly somewhat disheartening to learn that Laurence Fishburne won’t be back as Perry White in Justice League, but his rationale regarding the decision makes sense.
As much as he would like to return as the iconic newsman for the upcoming DC adventure, Justice League does not live and die by the presence of Mr. White.