If you're going to go all-out with the Les Miserables wardrobe, go for it, they won't kick you out.
As others have said, the audience is less casually attired than the average Broadway audience. Especially on weeknights, when everyone comes straight from work, or around the holidays. Jeans and t-shirts are fine, but I don't see why stepping it up a notch is something people are frowning upon. Especially since come intermission, you'll be with the more formally attired ballet, opera and symphony audiences in the Grand Foyer. And those b*tches will definitely judge you.
Like a firework unexploded
Wanting life but never
knowing how