I just realized that the day I am planning on going to Epcot is a Disney after hours event day. Now I'm wondering if I should wait and go the next day though that would be less convenient for me.
After Hours doesn't affect the day crowds that much since it occurs after the park closes. Those with tickets do get to enter at 7pm so there could be slightly elevated crowds at that time.
It has no effect on the daytime ops. At night after the show you will notice people lingering about who would normally be heading to the exit. Those folks have bought AH so they have 0 incentive to wait in ride lines during normal park hours.