If it had been on Broadway, that would have been one hell of a year at the Tony Awards. Millie, Urinetown, Mamma Mia, Sweet Smell of Success and Last Five Years. I'm not sure anything would have changed, except Brown may have won Best Score over Urinetown, with them keeping the Best Book and Direction wins.
Imagine if Norbert Leo Butz won the Tony that year for Best Actor over John Lithgow and then have the same exact thing happen this year. That would have been one funny situation lol.