It’s interesting how history is subtly rewritten. The story talks about how an early version of Justice League was too dark and Warner Bros wanted changes.
My understanding (second hand of course) is that they were making changes from the first day of filming. The script (which was still being worked on) was dark, and the expected rewrites during filming (it’s totally normal to keep writers on the production in a big studio film) were creating a lighter version of everything as they went along, at the request of Warner Bros.
Whedon was consulting while Snyder was still directing (as he was developing the Batgirl film) and then he stepped in when Snyder left to be with his family.
That’s all streamlined, as if they had actual Snyder version that were solid and set and then changed after he left. Nothing was solid, nothing was set. It was an evolving production. Snyder was working with Warner Bros, albeit from his point of view of things.
As for Affleck, I still like his approach to the character but if he’s fed up and wants to leave I wouldn’t blame him.
Reeves ability to recast the role illustrates, more than anything else, how different Warner Bros is to Marvel.
Can you imagine if Marvel hired a director and they wanted to recast Thor? They’d be lucky to get cab fair home.