My speculation:
There is no way to do a house in MiB imo based on just where they would put the queue for it and MiB during the day. Let's assume they start construction in July, which is later than they ever start. It's still the middle of summer, and MiB still gets up to 60 min waits on busy days due to crowds/ being right next to Diagon. Add in the fact that the park continues to grow in popularity, Twister and Disaster are lost capacity, and KONG/ nuHulk will be pulling people in, and you're gonna see a problem with not having most of the queue for MiB. Then for HHN, where could they possibly put a queue/entrance? I mean there's very limited backstage area by it for a queue, but I just don't see it happening.
However, if there's no conceivable way to control 9 houses plus their queues with all the construction going on, then 2 parks is actually a necessity this time around. 3 SSs, both tents, and parade building for houses on USF side. Then 3 SSs on the IoA side, and Poseidon as a possible 10th house. Have ONLY Hogsmeade, LC and Seuss (for SS entrances) open. Leave the rest of the park open for daytime guests till 7. After 7, possibly open JP and Kong for HHN guests. B&T in FFL, new show in Sinbad, Horror Makeup Show open, and possibly a show in Animal Actors, if it's still there. They just won't do the entirety of both parks, as that's an absurd amount of walking/ security/ TMs/etc. etc. But having mostly USF plus half of IoA with Hogwarts Express open could work.
For the houses, I'm guessing 4 IP/5 original (5 IP if it is 10 houses). The Purge and The Conjuring have the highest chances amongst new IPs. Other than that I have no real speculation. I think we'll see either a Nightingales, Urban Legends, or Catacombs sequel. My money's on the first 2.
5 zones plus chainsaws spread out over the park worked extraordinarily well imo; just don't have all 3 non-zone hordes use saws.