On Thursday, the ACC and Notre Dame announced an extension of their football agreement. It’ll now run through 2037.
As the N&O’s Joe Giglio points out, Notre Dame has no incentive currently to join a conference full time (the Irish are contractually obligated to join the ACC for football if they choose any conference) but that could change if the playoffs are restricted to conference champions.
However, the odds of the SEC and the Big Ten going along with that seem pretty minimal so don't hold your breath. The Big Ten, remember, approached Maryland partly because they felt the ACC had encroached on their turf by inviting the Irish.