The way I see him, at least this is the idea: The AOS/Thomas is very very very old, one of those lovecraftian level of ancient elders who found and possessed the Aggregate of Self and has made it his. Somewhere along the line, this terrifying power was contained inside the mirrors... all mirrors everywhere. That space beyond the edges of our universe. And for damn good reason, something like that with the power of the AOS is beyond terrifying. It is literally a walking madness engine, that even the other Elders out there would rightly fear.
He maybe free, but as stated in the text, there are ramifications for stuffing such a being into a spotty teenage boy. What they are even Thomas doesn't rightly know.
AOI Hugo might, once he has time to process it, but right now he is dealing with the AOI's 403 page not found error. And let's face it, the AOM Alec doesn't give a toss what is going on with the AOS, he's got more immediate problems, as in a missing boyfriend.