The other possibility is that UNC and Virginia have no desire to go to the SEC. UNC wouldn’t want to leave Duke (alums would revolt unless the conference imploded) and Virginia would never want to associate with the SEC.Yeah, if for some reason the Big Ten and SEC never pull a single jenga piece of UNC, UVA, FSU and Clemson I guess we're potentially stable. Seems like a massive "if".
The Big 12 somehow avoided that exact thing for over a decade with Texas always flirting. The massive difference is for most of those years Texas was actually raking in the most cash of all college athletics programs so it wasn't like they chose to stay in the Big 12 and slum it for less money, they were cashing bigger checks than SEC/Big Ten foes at the time they chose to stay.
Notre Dame is always out there as a potential "OK we are done" for the Big Ten. That's probably the best hope for the ACC teams outside of those four who would have a home. Even if the Big Ten does that, then the SEC has to say they're all good too...which does make more sense because they're already in Florida and South Carolina so they're really just saying no to Virgina, and North Carolina.
Again not putting money on it, but there is a small possibility