BroadwayConcierge said: "I, too, have heard thatSpongeBobhas an unannounced "closing" date due to the Palace's upcoming renovations. Unrelated to its grosses."
That is incorrect. If its grosses were better, the show would move. We all can list lots of shows that moved over the years; to site one, I seem to recall that Chicago moved from the Rodgers to the Shubert very early in its run because the Rodgers had been booked and Chicago was doing better than anyone expected, i.e., selling out. Had it not been doing well, it would have closed.
(I said 'seem to recall' because that is what I remember (it was 20 years ago), but it is altogether possible it moved to the Shubert to take advantage of it modestly larger size.