What I think is important to understand is that Florida State would be just the first step in Big 12 expansion.
First the Big 12 invites Florida State. Then the Big 12 says "We are happy at 11 schools. 11 is such a great number. We can't possibly imagine ever expanding again. But we will continue to monitor the landscape."
Without Florida State, panic ensues in the ACC. Now all the schools are ripe for the picking.
Now the Big 12 invites Virginia. "We couldn't pass up having both Virignia and West Virginia in the same conference. Now that we are at 12, we have the proper 12 to match our name. We are done expanding." says Bowlsby.
The next day, North Carolina and Duke are invited. "Okay, we are really done this time", says Bowlsby. North Carolina and Duke issue a joint statement saying "We had no choice because we heard North Carolina State and Virginia Tech were going to the SEC".
A few days later the Big 12 adds four more (Connecticut, Syracuse, Clemson, and Notre Dame). Notre Dame joins as a full member because no one will have them as a partial, and they don't want to stick with all the rift-raft left in the ACC.
With 18 teams, the Big 12 changes its name to the Big 18 (but also trademarks the names Big 24, Big 36, and Big 128 in case of future expansion) and splits into two divisions:
East: Clemson, Connecticut, Duke, Florida State, North Carolina, Notre Dame, Syracuse, Virginia, West Virginia.
West: Baylor, Iowa State, Kansas, Kansas State, Oklahoma, Oklahoma State, TCU, Texas, Texas Tech.
Scheduling is round-robin in each division (8 games) plus 1 cross-division game in football with a championship game pitting the winners of the two divisions, and single round-robin in basketball (17 games).
6 months later, a secret memo leaks that indicates that Boston College, now stuck in a depleted ACC that's considering merging with the AAC, was originally going to be invitee #18, but Connecticut blackballed them.
