Depends on what Presidents of the institutions in the major conferences want and what the legal landscape looks like. ND's hand can be forced by threatening to exclude them as an independent. Even ND becomes irrelevant if excluded from the group and if nobody from the 5 majors will schedule them that ND TV contract isn't going to be very valuable. Even ND can't draw ratings without decent opponents not to mention their athlete pool will shrink because top kids will not want to play second tier competition. Does the threat of exclusion/access draw antitrust scrutiny is the big question and what would that entail in terms of government review and possible intervention? ND probably doesn't have to worry about their hand being forced when a Coach like Spurrier makes a comment but, if more coaches and AD's bend the ear of their presidents and those leaders start banging the drum ND's days as an independent might be numbered.
What would be the point in that? It would undermine the legitimacy of the playoff, particularly if ND beat any of the participants in the regular season. I said antitrust and that may or may not be the appropriate legal challenge. It could also be tied to the tax exempt status of intercollegiate athletics which would impact the entire business model. Realistically speaking, all the schools(Big 5 as well as next tier) have to recognize the potential threat of outside regulation and I would imagine all of them would prefer to reach a workable solution that minimizes the chance that lawmakers/regulators would feel the need to get involved. The current pie(i.e., revenue stream) is pretty large. The big schools want more recognizing their sizeable spending/investment, all the schools have to reach a decision as to what piece of the pie they would be satisfied with as opposed to the government intervening and cutting the pieces for them.
I believe the executives of ND and ACC have an understanding and truly understand the ND situation and will not force anything on either party. However, if this thing called college athletics goes crazy, ND has a nice option if needed. Especially now, that so many leaders in the ACC from the presidents to the AD's and support staffs have ties to Notre Dame, and understand .
However, if the big schools threaten to leave the NCAA, the remaining schools have threatened a major lawsuit due so some arrangements regarding the football championship. THey are going to file for damages and I believe will ultimately head to the supreme court or congressional action. NEITHER IS PRETTY.
People keep saying this, but on what grounds would the remaining schools sue the breakaway schools? No one is keeping them from having their own league and playoffs. So it can't be a monopoly thing. No contract between them guaranteeing payment/play that I know of.
Now I could see the enough momentum being built in Congress to get some sort of law passed to get the right teams in... (and boy could they be better spending their time elsewhere)