Apparently, the exces at WB wanted the hype of this film to die down by releasing news of a Superman reboot. The WB execs were not pleased with the newly released Justice League which is scheduled to air on HBO Max on March 18, 2021. To be fair, they weren't pleased with Jack from the start since 2013 but they allowed him to roamed because he was under contract. Henry Cavil and WB have had issues for years; Ray Fisher made statements about abuse on the set from Joss Whedon, and Ben A. just quit because of "fearing of drinking" and an exec told him that he'll be an alcoholic again.

No wonder Christopher Nolan departed from WB.