the ACC would eliminate the protected cross-division game. It is safe to assume the ACC would want to make sure the Clemson-FSU game and probably UNC-UVA game (aka The South's Oldest Rivalry) is played every year as a conference game. If the ACC limits the protected cross-division game to those 4 teams, then it would create quirks in the future cross-division schedule.

The "quirk" I am referring to is that each year at least 1 team will be "bumped" from playing Clemson, FSU, UNC, or UVA to make room for their protected cross-division game. As a result, VT could end up playing Wake more times than Clemson, FSU, or UNC before the rotation is completed. The only way to prevent quirks from happening is for every team to operate by the same rules (aka everyone has the same number of protected cross-division games) when it comes to cross-division scheduling. If you want to see real world examples, then take a look at the Big Ten and Pac-12 future scheduling format. Right now the Indiana-Purdue game is the only protected game in the Big Ten. While the Pac-12 has decided that the 4 CA schools have 2 protected cross-division games so they can play each other every year as conference games.