Much more likely, short term, to have teams applying to take UConn's place in the AAC.
Gotta think Liberty mailed in an application with a huge check.
To the OP. Doubtful any team leaves the AAC due to no places to go. Big 12 (in current configuration) won't add any more as that will make the gap between the B1G/SEC even bigger.
I personally see a different scenario getting ready to happen in the next 2 years. The money is getting crazy different between the top and bottom of the p-5. It's going to be tempting (100+ million per decade) for KU to leave. Everything points to them trying to shore things up for that move as the AD is throwing money at facilities and putting out fires as fast as possible. That will be interesting to watch.