I think framing will still be very important given the limited number of challenges. I don't think the borderline calls will be challenged that often vs the more egregious umpiring mistakes and as such the good framers will continue to steal strikes, just at a bit of a reduced rate. One thought I had was that a bad framer can lead to potential strikes actually being called balls instead, so perhaps this subset of catchers could use the challenge system to mitigate the negative effects of their sloppy receiving.