i know you were already convinced but i loved my 50's prime time reservation last week that was at 7:30. the park closed at 7 and we watched everyone flood out of the park. got a near empty picture in front of the chinese theater even before our reservation.
we were leaving the park a little after 8:30 and there were just a few stragglers (and only about 10 cars in the parking lot). we wanted to go down towards tower of terror since i LOVE it lit up at night and it is my favorite attraction. but they had a security guard posted at the entrance of sunset blvd and i didn't want to bug him.
i know a poster on another thread had an Oga's Cantina reservation for after park close and got escorted out of the park by a CM. But before doing so, took incredible photos of Galaxy's Edge at night with no one else to be seen.