But we all know how entities can get around things like this. Speak in hypothetical scenarios, use go betweens, hire consultants "to do a study", etc. So no invite or backroom agreement, but schools know where they stand.
Plus if Big12 money is equal to or better than ACC money, then there is not a downside for schools that don't get Big10/SEC invites and are destined for Big12.
The PAC likely had just those kinds of discussions that lead them to believe they were still worth more than the B12 for their contract negotiations. How's that going for them?
This isn't a rinky dink deal that gets done between the president of a school and the head of the network on a handshake that no one's going to look too closely into. No one person is able to speak for any one side.
You've got all sorts of people working on this. Analysts, consultants, marketing, legal, etc etc etc. You've got those people for the networks. And each of the conferences. And all the ACC schools that want to leave. And the B10 Schools. And the SEC schools. And the B12 schools. That's hundreds of not thousands of people working on this deal. There's no way that it doesn't come out through leaks or FOIA requests (lots of state schools involved, after all). These people aren't going to purger themselves in a civil trial. While they can refuse to answer a question, unlike pleading the 5th in a criminal matter, juries in a civil matter can read into a non-answer in finding their verdict.
Without some kind of an assurance, schools aren't going to greenlight jumping out of a, at worst, P4 conference for the unknown. The firmer the assurance, the more likely it is to be a conflict of interest. A hunch and a notion isn't going to cut it for an institutional decision.
As much as some of the ACC schools have to lose by being stuck in the ACC, the ACC schools that get left behind have just as much to lose by the ACC dissolving. There's no way they don't file suit immediately. Losing that suit would be catastrophic beyond being stuck in the ACC for another 30 years.