Is it really that simple though? I think there is one big red flag that everyone is ignoring. Ben Affleck. Why is he important? Because everyone keeps saying "what will the studio do?" Has anyone stopped to ask: what will the actors do?
Affleck has straight out said, doing press for JL no less, that he is looking for an exit strategy from the DCEU. Do you think he is the only actor who feels this way? Of course not. But he can say it because he is Ben Affleck and his career is on much stabler grounds than Cavill, Stevens, Miller, Momoa, etc. But, for that precise reason, he can't be the only actor who wants out.
These movies continue to get savaged by critics and underperform at the box office. That isn't good for the career of a young actor. Ask former Hollywood it-boys like Sam Wentworth and Emile Hirsch how being the face of big budget, high profile, under-performances worked out for them. It sets their career back years (sometimes doing irreparable harm). These people signed up for this thinking it would do for them what the MCU has done for Evans, Hemsworth, and Pratt (make them household name A-listers). All it has done is drag down their profiles by association. That's why Affleck wants out. He clawed his way back to credibility following his Daredevil through Gigli run. He doesn't want the DCEU taking away what he worked so hard to rebuild. And as I said, the other actors are already on much shakier grounds than Affleck. Affleck has credibility to lose. The others don't.
Just because Affleck is the only one publicly saying that he wants out, doesn't mean at least a couple of the other actors aren't telling their agents "get me out of this."
The only exception is Gadot, who seems to have been the only real beneficiary of the DCEU (well, her and Harlee Quinn Halloween costume makers).