Last year they chose the theme "ONE NIGHT ONLY." I don't think it needs to be related to the season, but just a way to celebrate Broadway.
It'll be incorporated into the Opening Number, I'll bet. And the Set Design.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle