Even if the show isn't selling out, I don't think there are any shows that are lined up to take over, so it's pretty safe as long as it's not losing too much money.
The show basically saved the Wilbur Theatre from being closed forever. Perhaps some other theatre companies will think about using the Wilbur as a theatre again.
"The sense that everything's going right is a sure sense that everything's going wrong."
-The Goat, or Who Is Sylvia?