Re: Texas, I don't think they move, but I wouldn't be shocked if they did. If there's one thing I know, it's that they act on their own terms. That said, what if Texas decided to join the ACC with a similar deal as Notre Dame? They could tell the rest of the Big 12 (or at least enough of them to win a vote) that it's in their best interests to dissolve the exit fees.
Texas could flatly state, "we are leaving, even if it means we have to wait a few years to reduce the exit fees. When we leave, this conference is done. If you let us leave now, you can likely find a safe landing in a stable conference. If you wait five years, all of the other conferences will be full, and you're going to be in deep shit. Let's all bail now for free and get on with our lives."