The principals have contracts into September...not that that means they can't close early, but I would doubt they are closing now. There have been no notices on other boards and if it were closing this Sunday, they would have to notify the public and refund money.
It's true you CAN close a show without notice but reputable...large...Broadway shows usually do not handle things that way, though some off broadway shows have been known to do that and surprise audiences when they show up and find out there is no curtain that night.
If the show were not selling after 6/26 though...Telecharge would have to shut down sales!
"Life is a lesson in humility"