The B1G started the new wave.
Missouri (I don't care if its Governor/President/AD - I sure didn't hear anyone from the University loudly defend the Big XII during that time) tried to jump on the new wave publicly and it blew up in their face.
You would think that Missouri learned their lesson and THIS TIME would not go public with anything until they really do have a "Done Deal" in their hand.
The SEC has 3 PRIME states in their region to go after:
If the latter 2 states' schools are solid in the ACC that makes Missouri target #1.
the OU and OSU regents did the same thing as far as having a lengthy closed door session that ultimately led to nothing. They will probably come out and say they are giving their president the power to make whatever decision he sees fit for the University. That is the same thing every other school has done. Doesn't mean they are leaving until they say they are.
Well technically OU, OSU, UT, & TT did it getting ready for the PAC move. The difference is that MU did it against an ultimatum (again from UT) to sign up or get out. They also are most likely going to have their application to the SEC accepted.
Everyone else gave their president the power to make decisions, but it sounds like they took it a step further and gave the big 12 notice they are looking at other options. the same the A&M did right before they announced SEC bid.