He's not toning down anything. Ive followed him on twitter for several months and 2 things became obvious very quickly:
1. he likes a drink
2. he's way gay
he is actually quite reserved but when he has a drink he gets more extrovert. So no, you wont be seeing him being flamboyant on Good morning America unless he gets plastered in the green room beforehand.
The difference between how flamboyant he was acting then and how reserved he is now I guess it is possible to hide the queen inside of you. I hope this doesn't turn into a big media story and his chances for success get ruined though, he's so talented.