Right now Notre Dame is the 15th member and could be
placed in 2 different regional quads. If the ACC add Navy or WVU, then Notre Dame would be placed in Quad 1. If the ACC adds UConn, then Notre Dame would be placed in Quad 2.
You have to keep this information in mind when looking at the scenario where VT and UVA don't play each other annually as conference games. So even though I used Notre Dame and WVU in the example, Notre Dame's slot could be replaced with UConn. While WVU's slot could be replaced with Notre Dame and Navy.