Maybe. The other possibility is that, since Cavill has officially confirmed he's returning as Superman, this creates scheduling conflicts and choices had to be made. Certainly wouldn't be the first time something like that happened, and from a career pov picking Superman is probably the surer bet, considering Netflix' diminishing prospects and mercurial habit of dropping shows out of nowhere.
Or maybe a little of column A and B.
Idk, it kinda seems like the Superman movie franchise is cursed. Not quite to the extent of any games, but even Superman Returns had better critical reception than any subsequent entries that Cavil was attached to.
I just don’t trust the DCEU can reliably put out bonafide hits like the MCU mostly has even in phase whatever it is now, especially with the way WB has been lately.