When Wong went down Narvaez got more playing time and has shown he may be a better option at catcher. If an outfielder goes down the have Anthony, if an infielder goes down they Mayer and Grissom. When pitchers went down they had Dobbins and Fitts step up.
First base is seemingly the only position they didn't have great depth at, and to be fair how often do we see infielders move to 1B in season? not that it's terribly common but it's got to be the easiest transition to make. It's not like the Sox lied to Devers about DHing him all year they would have kept him there if Casas didn't go down. Asking Devers to slide to 1B is the type of move every single organization and every single GM in baseball is going to ask a guy like Devers. It's the most natural movement.
Devers to 1B make this team so much better, the open spot at DH gives the Red Sox so much flexibility to figure things about between the likes of Yoshida/Grissom or to make a spot for Anthony/Mayer.
I don't blame Raffy for being upset, I was one of his biggest defenders during the offseason. But there's zero reason he shouldn't move to 1B, it's easily the best move for the team and one he should jump at if he really wanted to play the infield.