in a post on Threads, James Gunn explained that the reason for the delay is simple: the script for the film isn’t fully finished yet, and when combined with a general two-year cycle of production on big films, it made sense to move the film’s release date back to 2027…
Here’s GUNN’S statement…
Sure. Yes, it is true. The only reason for the delay is there isn’t a full script (those of you who follow me here probably know that already),” said Gunn. “Matt is committed to making the best film he possibly can, and no one can accurately guess exactly how long a script will take to write. Once there is a finished script, there is around two years for pre-production, shooting and post-production on big films.”