Well for the past couple of years, they had a night show in the Amphitheater (Cirque Dreams Coobrila which was pretty kickass but that's beside the point), which is very closely located to the Giant, and that would obviously disrupt the show, but even before then, they would close it at 8 as there's no lights on the ride, or around that area where a majority of the ride is located. I'm not completely sure though.