If this whole thing was just a negotiation tactic, I expect it would be resolved relatively quickly. At least, I hope it gets resolved quickly...
There's one potential reason for the breakdown that I don't think has been discussed, and that's scheduling. Reeves is going to be busy with Apes up until its release, plus a few extras weeks after with promotional trips. Even if he was to go from Apes to a new film immediately the earliest he'd be able to start pre production would be July, assuming he doesn't want a break. WB might not be that patient, especially if they're holding out hope for a 2018 release.

