I'm not sure how they have premieres for TV shows, but they do, and Lea Michele was determined to own it with her pushed up deep cleavage. Bravo I say. I'm not even sure she's associated with American Horror Story. I think she just showed up to steal the red carpet in a dress she found which flattered her funbas. Bravo, I repeat.
There is only one ceremonial protocol that should matter in Hollywood. If you look hot and chesty in a dress, put it on and get yourself out in front of the cameras. Invite shminvite. Lea Michele is looking rather chesty alluring these days. It won't do any of us any good if you keep those sweet peaches under a sweatshirt at home. If you got 'em, flaunt 'em. Enjoy.