MY logic is that the Sox are not a good defensive team, and Devers and Bogaerts are both below average defensive players at two key defensive positions. Of course, they are also the two best hitters on the team, so it's very, very likely nothing happens.
The big issue is how well Bogaerts could handle third, since he has not played the position in 8 years and reportedly does not like it. I have no trouble believing Devers could handle 1b, as it is the easiest position to play and is where every hitter with fielding problems gets moved to (other than DH).
Now if the Sox were losing, maybe they make a drastic change like this. But no way they do anything like switch the positions of one of them while the team is winning. Although it is interesting tht Cora has no problem bouncing Verdugo around the outfield and won't move any staters around the infield.
So upgrading this team defensively is not very likely. Maybe a 1B (won't be Casas). Maybe a CF (should be Hernandez, but probably won't be).
It also makes it difficult to figure where to plug in Duran. As of now, he is not necessarily any sort of defensive upgrade in CF. So he would have to replace either Verdugo or Renfroe. And it does not help his case that Renfroe continues to hit. In fact, right now, bringing up Duran probably weakens an already soft defense by forcing Verdugo into CF full time.