Of course this is their preference. But don't you think the conferences can force their hand? It would be easy for the Big XII to grab Louisville and ACC to take UConn, thus obliterating the Big East for good. Would ND stay and play with the BB Only BE schools? Maybe, but it would hurt a strong men's and women's hoop program and good soccer programs, which DO matter to ND. If nobody else will give them the Big East Special, what option do they have? Especially if the playoff is stacked against them and in favor of 4-5 conferences. The Big Ten won't give them the Olympic only deal, as they are in the #1 spot should ND finally join for football. The ACC and Big XII...maybe.
If the ACC-BE merger 3 years ago would be so popular, why wouldn't UConn plus ND to the ACC be the same thing? Who's missing that the Irish care about? WVU? Doubt the Irish have any interest in the hillbillies. The merger you mention has already happened except for UConn and Rutgers.