Well this was almost a year ago, but we had an 8:00 ADR last June and didn't actually get seated until 8:30. We weren't rushed in the slightest...could hear the booms of the Illuminations fireworks going off...by the time we finished dessert the park was completely deserted, so we must've been there at least until 10 or so.
There were plenty of other people still there as well, so it wasn't like they were trying to close the place down around us, either. I think EPCOT closing at 9 means they'll take their last round of seating at 9 or as soon as they can get people in after 9", not "9 pm - time to start vacuuming and turning chairs up".