For MK, I think that September is in the heart of the Halloween parties, and they make more money on them than they do on DAH, so if they have any DAHs, it will be limited. Both cost about the same, but the party crowds can be larger because of all the other features of the event. Once DAH gets much bigger than it is, it loses much of its appeal.
For HS, Star Wars is going to rule everything for the next two or three years. I can't see any reason for WDW to offer reduced crowd events for the foreseeable future. Not saying they won't, but from a money standpoint it doesn't make a lot of sense. They could easily to a Star Wars themed party with 30,000 crowds, but it wouldn't make sense to do the kind of limiting thing DAH requires.
AK will probably have them. Epcot may, but more likely when the new rides open.