In addition to a whole lot of other pluses, I agree with UCONN's low cost separation. To this, I would add the relative intangible of a low cost of emotional separation-severe regional or conference separation such as UNC would likely have.
As for your clear point that there seems to be no one that is worth adding, almost no one saw Nebraska or Maryland making their moves to the Big Ten when they did. Depending on the ACC and Big 12 GOR situations, there could be several schools that could change there position from their current public posture. But likely, the first time that you hear from it will be in a press conference.
If there is extra money to be had (and guaranteed to any new teams), potential schools will be made aware of it through low-key intermediaries. UCONN needs just ONE school. I'd never bet against
the entire field in this situation. Why? Because there are so many schools that would be better off in the Big Ten than where they are now.
The Big Ten does not want any publicity and of course, neither do any schools giving or receiving feelers. I note that on many boards that people express scenarios that something has to happen. Maybe it does. But I think the stronger likelihood that a school just
decides.