Nothing forces Notre Dame's hand.
Not the playoff, not expansion, not something like the Big 1G/Pac 12 deal and definitely not anything that the Big East might do or not do with the possible exception of completely disappearing.
Notre Dame can fill their schedule every year with less than a dozen phone calls. All but a bare handful of athletic directors would chew their own foot off if Notre Dame made it a prerequisite for an ND game.
Stop worrying about Notre Dame and stop looking to them as our possible saviors from our current predicament. They're fine and they're not going to help us.