As a resident of NE, I hear a lot of the Boston sports news despite my best efforts to avoid it.
The comments by Devers continues a history of tension between this player and the organization.
He was signed long term for his real talent as a hitter, but also within the context of letting both Mookie Betts and Xander Bogaerts go and the organization receiving well deserved fan & media criticism of cheapness and poor talent evaluation. Xander was allowed to walk as a FA and the Betts trade (Betts + David Price for Alex Verdugo, Jeter Downs and Connor Wong) has not been popular.
As a 3B, Devers has struggled the last several years which led to the signing of Bregman who is an upgrade there. Devers did not go to DH willingly, much public back and forth with the organization and tension with Craig Breslow in particular (Bosox Head of Baseball Operations). Alex Cora, the manager who was extended to a big contract too for this season, has laid low during the conflict.
Devers also struggled at the plate as a DH to start the season, but has recently been hitting much better. Now, with the injury to Casas which was really ugly, there have been internal discussions with Devers on considering 1B. Devers comments blow into the public eye again, targeting Breslow once more. Not a good look at all. Breslow has taken the high road trying to mediate the situation with who is supposed to be their core star player. Devers likely worried about how learning the new position with impact his hitting, but the organization asking for a more team oriented approach. Devers saw how Bogaerts and Betts were treated and may not have a high level of trust with TPTB, but they did give him the money (respect) and have expectations he will play ball (pun intended) with them.
The organization is helped by two prospects (Kristian Campbell & Marcelo Mayer) doing quite well in the farm system that could learn the 1B position perhaps easier than Devers. The permanent DH does provide a spot for Devers, but IMO what player would turn down a chance to learn a new position and thus make himself even more valuable to his team? That is the strange thing about Devers' attitude.