Anyone who thinks Notre Dame is going to be in the big 12 is out to lunch. There is no incentive and that is not where their alumni are. Plus the Big 12 does not play most of the sports Notre Dame does.
They will do anything not to have to change but Notre Dame is big into sports like lacrosse and soccer. It would hurt their basketball program too. They love the Big East for that.
That is why the ACC is their option if the Big East comes apart.