I think it's worth pointing out that I've NEVER heard a negative thing about BYU from a Baylor fan. It couldn't be more obvious that the Baylor Admin and AD are VERY HAPPY to have BYU. I'm sure it would have happened in the past if not for UT. Yeah mostly UT.
I have also heard the Baylor AD talk about the importance of Fit. I don't know who votes at this point about adding new schools — old & new schools or just old — but I feel certain Baylor and most Big 12 schools would not be in favor of adding a school who is a cancer. UT and OU were such a cancer doing things like blocking new members. And UT literally ran Texas A&M, Nebraska, Missouri, and Colorado off. And Texas A&M was a GREAT school to play against with long relationships with the other schools. Why add another cancer?
I also don't see the Big 12 adding any CA schools because of similar reasons. They have been anti Baylor and TCU during any discussion within the past decade or more. Our schools will not forget that and I can't imagine why BYU would want to add them either.