The MW just signed a 6 year deal. For any team to leave the MW now would be a mistake unless it is for a P5 conference. There isn't enough money in any other conference outside of the P5 to truly make it worthwhile, when you factor in travel costs, and possibly dropping your other sports into a lower conference.

If the MW didn't let BYU keep their other sports in the MW when the went Indy, I seriously doubt Boise would get that option if they go elsewhere either Indy or AAC for football only. The MW and Boise both know this, so when it comes time to renegotiate the next media deal all parties will likely be on the same page. It is a bunch posturing by both sides that will ultimately be much ado about nothing.

If a BOR conference that is coast to coast does get created then all bets are off as teams will scramble to get in, but their has to be a true western portion with at least 4 teams. The BOR could happen if Texas and Oklahoma leave the B12 or the AAC decides to go west with 4 teams.