...so any B12 expansion would not motivate BYU to start negotiations with the MWC until late 2018, at the earliest.
If ESPN puzzlingly declined to renew on acceptable terms and thereby pushed us back to the MWC, I'd guess we would initially rejoin as a football-only school (a la UofHawaii) until we could exit the WCC gracefully, but we don't have to worry about that scenario for at least another four years, so relax!