THR and such have done a great job reporting how the coporate stragety changed with new leadership at DiscoWB, but that's only half the story.
I heard about the "Batgirl" test screening from fan groups and it wasn't good. To be blunt, the film wasn't a Batgirl movie, it was a film trying to deconstruct the Batgirl character into something else entirely. Fans were literally horrified.
Adding to this (and not to be understated) is the success of "Top Gun Maverick," which showed keeping characters at their core design, but surrounding them with more personal and modern based storytelling is a huge box office win. Generational appeal is the future of these franchise brands, as both young and old fans will support solid film sequels made in this vein.
To put it bluntly. The clock has run out on the "We're going to redefine all your favorite characters" chapter we've been living thru.. Instead a focus on making theatrical more (pardon the pun) actually "theatrical," with focus on profiitability is the new score. Just like what "Top Gun" accomplished.
Yes Batgirl could have easily been put in re-shoots, added a good 10 million to fix the project for theatrical release, but the overall design of film doesn't fit the new score. Characters, high concept, and fan support are back in full play again.
So expect a ton more lip service on how this was "a budget decision only," but I feel it was way more than that.