There is some possible irony here.
I think if Threet stayed at GT, there's at least some possibility he beats out Taylor Bennett. TB, as good as a kid as he is, struggled at in his year as a starter. If Threet did beat out Taylor Bennett, and GT won 1-2 more games that season, Gailey likely keeps his job.
Threet would then go on to star in a pro-style offense for which he's well suited.
Instead he bolts GT for Michigan and gets the shaft when Michigan goes to a run heavy offense. Meanwhile, GT, the school his presence MIGHT have kept in a pro-style offense, fires Gailey and becomes a run-based offense.
Funny how life works. He bolts the perfect offense for him by screwing GT, then himself gets "pay back" at Michigan. In the process, he loses 2 yrs of eligibility.
Well, best of luck to him, I hope he can succeed and make it to the NFL.