We had a 7:45 reservation at 50s prime time the week after thanksgiving , I think it was Tuesday. The park closed at 7pm, some of us finished up shopping while the rest of the group rode star tours , getting in line around 6:50pm. We met up at 50s at 7:40, there were still people lingering on Hollywood blvd, but security would not let you go back towards galaxy’s edge or toy story land, only forward toward the exits. They were waiting to clear a table for the 8 of us, we didn’t get seated till 8:10pm. It was the best meal !! ( having been there over 12 times) Our waiter was from Morocco and funny, another large family of 16 were in the room behind us , he had them laughing too. We even got dessert, thus, not leaving the park till after 9pm. Sure enough the park was quiet and we made our way out with many cast members waving at us. It wasn’t until we left the entrance stands, that a lady asked us where we were headed and radioed to the bus ahead . Then we were told we were the LAST FAMILY leaving the park that night. How cool. Wish we would have gotten a button or something. So yes, it’s true they know how many people are still in the restaurants and will always have a bus or I’ve been told a van available to take you back to your resort,
Hope this helps, let me know if you have other questions