Aside from needing a theatre, there’s also the fact that David Cromer is obligated to Goodnight, and Good Luck, which has an opening night of April 3. It makes him effectively unavailable during the entire window of time when a show angling to open before Tony cutoff would be rehearsing and starting previews.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."