72 is way too many schools. And even at 64, Notre Dame will remain independent in football. The ACC alignment will be 15-1. I can envision the ACC in three pods of 5, just as we might see the PAC in three pods of 6 (5-2-2, 9 game schedule). The smaller pod size for the ACC works out well because of the rotating games with Notre Dame which MIGHT go to 6 per year (2 games per pod per year). In that alignment I would still expect the ACC to keep a designated cross-over game.

You might see an alignment like:
West Virginia, Boston College, Syracuse, Pitt, Virginia Tech
Miami, Duke, Carolina, Georgia Tech, Virginia
Florida State, Clemson, NC State, Wake Forest, Louisville