When you combine catchers' offensive value as measured by b-Ref, and defensive value as measured by BP (which excludes pitch-calling but includes framing, blocking, and throwing), the Sox rank 17th in MLB. If you buy that some of the tremendous success of the pitching staff is due to pitch-calling, then Vazquez and Leon have been a mild asset. They rank 5th to last in offense but 4th in BP's defense. It's not broken, so you don't fix it. You hope that the pair hits better, as they've shown the capacity to do so in the past.
I wouldn't mess with our pitch-calling tandem.
I also wouldn't be surprised, if we end up better than 25th on catcher offense by season's end.