I think in theory that would be correct. I'm definitely no expert but from my experience a contract means very little in the U.S. with the right combination of money, lawyers, and patience. I also haven't read the GOR contract to know if there are any liquidated damages provisions that would reduce this to merely a numbers game.
I think those trying to enforce GOR will find Judges (especially at the higher courts) that are unlikely to force someone to stay in the contract with no means of exit for such a lengthy period.
In a manner, it's sort of like how they deal with absurdly long non-compete clauses or contracts. Sure, you can make them and everyone can agree, but if someone wants out of it 5 years into a 10-year non-compete, they're getting out of that 9/10 times if they hire the right attorney. It really depends on the jurisdiction for the case.
Also, I don't imagine that it would be a quick process, so unless they got an injunction preventing the leaving party from leaving, the leaving university would be able to leave and do whatever they'd like until the suit was resolved. At that point, the damage would have been done to the original conference and most sound minds would push toward settlement.
Look at Maryland and the ACC as an example -- def not the same exact thing, but along similar lines for breach of contract.