Two Tony winners for Best Musical will probably never be revived anywhere, ever -- Fosse and Jerome Robbins' Broadway. As for the others, I don't think Contact, Hallelujah Baby, or Redhead would ever be revived on Broadway, although they might be re-mounted elsewhere.
Of the currently running Tony winners, I think that Avenue Q is the one that is least likely to be revived in years to come -- the book is very of-the-moment and would have to be dramatically re-written to not be too dated twenty years from now.
"What was the name of that cheese that I like?"
"you can't run away forever...but there's nothing wrong with getting a good head start"
"well I hope and I pray, that maybe someday, you'll walk in the room with my heart"