There is a generic clause in 1.2.3 of the B12 bylaws that says every school agrees to remain a member of the conference for 99 years. Then Section 3 talks about withdrawal from the conference and lists the penalties for withdrawing from the conference with references to the grant of rights.

Note that Texas and Oklahoma were original parties to the bylaws, and they also agreed to the 99 year clause. But it didn't stop them from leaving the B12. The only actual impediment to OU and Texas was the grant of rights. So the fact that Utah is exempted from the 99 year clause doesn't actual mean anything special. They're still bound by the grant of rights, and the grant of rights is the real teeth holding the conference together. Everyone knows by now that conferences are stable only as long as they have a GOR. ONce a conference's GOR expires, everything becomes unstable and it's open season.

So the fact that Utah is exempted from the 99 year clause in the bylaws is a distinction without an actual difference. They still signed the GOR and they're still subject to the the same restrictions as everyone else in the conference.