This is probably just the A's realizing that since they cant get anything for him player-wise, theyd rather not pay him for the rest of the season, plus he had a vesting option for 2023 that was very close to coming up, they would have had to pay him 15 million next season.
This is a massive salary dump for no real reason other than not wanting his 2023 option to vest. That's probably why they couldnt trade him at the deadline too, as teams would want no part of that vesting option.
Doesnt this kind of thing seem like the kind of thing that should have a grievance filed over? LIke, he's no star player anymore sure but he's only a shade under league average OPS this season, it's not like they can justify the release due to his on-field performance. This is simply dumping a guy to get around the vesting option for 2015. I dont think this is a good faith move.
One caveat applies, in that if they allowed him and his agent to quietly ask around to see if anyone would pick him up if he was released and they found a team that's ready to take him on.