Found on Twitter. So the Wall Street Journal is now reporting that Whedon was hired against Zack’s wishes. TBH the “everything’s fine” narrative the studio put out last Spring when it was announced Zack was leaving always sounded fake to me, and now it’s clear I was right.
So this seems like what really happened: Zack’s cut still wasn’t deemed FUN enough for Johns and WB execs, they decided to bring in Whedon to make more like Avengers. Zack was not happy but was willing to go along, presumably for professionalism and if he was there maybe he could salvage some of his vision. The the tragedy happened, he realized he just didn’t have the energy to do reshoots that would essentially be a never ending battle with his bosses, and left the project. And with him gone nobody was there to defend his vision and so most of his footage was junked, and what little was kept was almost entirely dubbed over with Whedon’s dialogue so only a handful of scenes are remotely Zack’s.