A&M is probably what killed the OU move due to their very real fear of losing the Texas game.
They should have called the bluff. UT is going to have one helluva hard time scheduling if/when they go independent (which is where I think they're headed). They'll NEED A&M and OU more than A&M and OU will need them. Just like ND needs USC, UT will need OU and A&M. Otherwise, they are left with a schedule of nobodys.