I question if the historical data is right (not sure how to look it up). We were there for there from about June 16th to July 4th 2016 and MK definitely did not close at 10pm every night. It was typically 11pm, sometimes midnight or even 1-2am. There may have been a day or two where it did close at 10pm, I don't recall exactly, but I'm certain there were later nights...we stayed to closing once or twice and it was 11pm.
I would expect they'll extend hours again this summer, but that's just a guess.