Most things remain open, but not everything will stay open until 11:00 pm. I know some of the TS locations stop seating around 10:00-10:30 pm. I think some of the QS remain open until 11:00 pm.
I don't know if things have changed, but Cava Tequila used to close during EMH, but the R&C Pub remained open.
In terms of the rides, the movies (Oh Canada, Reflections of China, Impressions de France) do not remain open. The rides (Malestrom, Grand Fiesta Tour, American Adventure) do remain open.
If you're going at F&W Festival time, most of the food booths close with the start of IllumiNations. A few booths remained open (I think I saw Italy and Mexico) one time when I was there, but most do not.