Either BYU gets an invite along with some other P5 level teams that are ready to move up..
or the Big12 crumbles to nothing. The Pac12 and Big10 take the leftovers and maybe 1 or 2 go independent.
With all the talks and rumors about the other Big12 teams wanting to move too, I think BYU is going to probably end up staying independent while the rest of the conference disappears.