Is it possible Snyder was under similar orders and that's the real reason he walked? Remember he continued working on it for a while after his daughter's death.
And would it have turned out that much different if Snyder had stayed and toed the company line?
IIRC Snyder was quoted as saying that he left in part because he simply didn't have the energy to keep fighting for his vision of the movie, so that and his daughter's death were why he decided to leave. If he's stayed I think WB still would have eventually forced a parting of the ways over "creative differences", so no I don't think it would have played out much differently.
If only the announcement that Whedon was only brought on to help with the script was true. If they actually collaborated on it I think it could have been amazing, what with Zack's visuals & action scenes and Joss's ability to construct a tight narrative. The two of them together probably could have convinced the suits that a 2hr 30min to 2hr 45min run time was required. The result probably would have rivaled IW in terms of quality, and we'd now be discussing our theories for the COVID delayed JL2 release this summer. If only...