Break down the situation.
1) Once the Catholic 7 notify the Big East they are leaving, the only voting members are USF, UConn, Cincinnati and maybe Temple (the "Football 4"), until July 1. Those 4 can do whatever they want after that in terms of revising bylaws, including exit fees. They also get to keep everyone else's exit fees. While there is some case law supporting a claim by the departing schools to get their exit fees back, a lawsuit is unlikely because of the threat of a countersuit by the Football 4.
2) Tell Tulane that they are sorry it didn't work out, but Tulane is no longer invited. Tulane may justifiably sue, so the Football 4 may have to dissolve the league rather than rescind Tulane's invitation.
3) Form the league they want with the best of the rest. There are NO legacy attachments. Goodbye Tulane. ECU, you are on the cusp, but will probably make the cut.
4) Sign a GOR contingent on a minimum revenue threshold. If the NNL (New New League) generates $10MM per school, then the GOR is in effect. If it generates $4MM per school, everyone is free to trade. A network, particularly NBC, will want some level of commitment, but this will also force NBC to make a meaningful financial commitment of their own. Ignore the ESPN and CBS articles. An all sports league with the schools on the docket will still get a meaningful payday. Rutgers and Louisville were not THAT valuable that their loss will cost the Big East half its revenue.
5) I would go big. If this is going to be an all sports league, I would go to at least 14, and maybe 16.
6) I would also make this performance based in terms of revenue split. The schools that win and generate TV appearances get a disproportionate share of the revenue.
7) the GOR is important because it will force action by the ACC or Big 10. Remember how they said "UConn will always be available". Well, we need to change that situation. If the ACC sees that UConn and Cincinnati are about to sign a GOR, it will force action on their part.