I think the move could be similar to the Nebraska add. By itself, Nebraska was a solid addition, but it was also a nudge to tip off massive realignment and see if it could shake Texas and/or Notre Dame loose. The net result was that the Big East has been poached so frequently of all football members with a pulse that Notre Dame was in danger of losing its safe harbor where it had parked its basketball and non-revenue sports for years.
Tapping Maryland will do the same thing to the ACC. FSU and Clemson have previously expressed interest in leaving (perhaps for the Big XII) while the SEC could always make a run at two more.
Ga Tech could be in play, but I think that is perhaps a tease like Missouri wound up being. They've tipped their hand and can now be used as leverage by the B1G.
Notre Dame is, and always will be, the grand prize.