The Big East is a non-starter. It's almost a completely homogenous league now of small, urban, private Catholic schools (just Butler isn't Catholic). They all have similar issues (urban space constraints, private school resources constraints) that a flagship state school like us doesn't.
If the BE expands, they'll surely look at similar schools in new markets (St. Louis and Dayton probably first in line). Or they'd probably even reach for a Siena or Detroit before they took us and disrupt their balance of power. They don't need us for market penetration.
The BE would clearly have some temporary benefit for us with hoops, but long term we don't really want to align ourselves with a group of colleges we have so little in common with. Any time there was a vote over something we wanted that the rest of them didn't, we'd lose.
Where we end up by dropping into FCS football is probably eventually to some sort of a league of UMass, URI, Buffalo, Albany, Delaware, George Mason, VCU, and other reaches after the A-10 fragments and the state schools form their own league.