What if previous masters have already invited some of the Olympians? Would you be able to rescind the previous allowances, to get rid of other Olympians that might have been allowed into the labyrinth?...
we were told in the game what happened that caused the past masters downfall though, even though I think there is no distinct timeline where the past master was active before he flipped out, I have a feeling it would have been too short of a time for athena to get her hooks into him especially with the metal illness issues. I will say that when the master kicked everyone out I can make a logical guess that counts as invited gods too
but you see, that master was the brother of the previous one and living in the hotel before he inherited it. Athena could have been tampering with him before he became the master.
also, it's easy to misdirect giving only a bit of the information. it's called paltering, you say something that's truthful but you don't tell the whole thing. in this scenario, what if his mental instability was a work of her?