I'd be surprised if the SunBelt expands beyond 14 teams. So much league revenue, like NCAA tournament credits, is fixed so unless adding them leads to at-large bids (not happening), you're just splitting the same size pie more ways. The SunBelt could have interest in Miami/OU, but I'm inclined to think that it would be a contingency to back fill in the event they get raided by PAC-12, MWC, or AAC.