Possibly. Last time we were there, we were trying to quickly hit all the Fantasyland rides before leaving. We had one last ride, Casey Jr. Circus Train. It was about 5 minutes before park closing and the CM had already shut off the line. We were walking really fast up to the line when he closed it, while the train was half full and had not left yet (which was kinda frustrating). So there are no guarantees that they won't shut off the line early.