UFC has no say in the matter. The only power they hold over the commissions is the money they bring in for events which does hold some clout.
Vitor did not have a license with Nevada at the time of his assumed failure. By law, if a fight is announced then they have the right to test and it will play a factor in his hearing.
If his testosterone was through the roof when they tested they will definitely bring it up along with his other failure in the past.
I'd assume he's going to explain that he was on TRT and approved to use it in other states and now that it is banned, he is clean. They will likely give him a conditional license and tell him he will be subjected to numerous random drug tests.
If they end up denying him his license and fight, there's literally nothing he could do at that point. Texas might license him but I don't think the UFC would do that. He would basically have to retire or fight overseas in countries that don't test. Bellator and WSoF are not options since they are bound by the same commissions.