Expansion is dead for at least the next 8 years because of TV contracts. The ACC member schools have signed their TV rights over to the league in a deal that keeps those rights with the league even if they depart. No conference is taking a team that can't bring the rights to show their own games.
The Big 12 and Big Ten have a similar arrangement. The SEC is the only conference with no grant of rights or exit fee. Any SEC school is free to walk away at any time. Obviously, that isn't happening.
Putting all of that aside, expansion isn't about football as much as it is about TV markets. The SEC wouldn't add a Florida State, Miami or Georgia Tech because the league already owns a share of those markets. They'll be getting the in-market rate from cable companies for the SEC Network in those states.
Similarly, a team like West Virginia makes no sense because they bring less than 800,000 TV homes in their entire state. Missouri got the nod well ahead of them because MO has 10x that number, including the large media markets in St. Louis and Kansas City.
North Carolina would be a new state, but their legislature won't let NC and NCSU split up. Ditto for Virginia and VT. Don't need to take two schools to dominate a state for TV expansion.
Expansion came to a natural stopping place, and it's going to be stalled here for years to come. Everyone got rich on new TV deals, and they won't itch to make moves until those deals are set to expire and that's 8 years away.