If we are playing the "what if" game, when have the Sox ever sold off a top pitcher for prospects during a run of expected contention? Literally the only time I can remember them selling what was viewed as a front of the rotation starter in Mike Sirotka, they got back what they thought was a superior pitcher in David Wells, and not prospects.
I am not sure why you are crapping yourself selling a pitcher in 2023 because of 2026, when the expectation is that this should be a contending team, when there is nothing to indicate they will do so. Trying to tie in them not spending this winter to mean they will be selling a few years down the road is just crazy. The only way they are selling at that point is if the team feels they can't compete.