I'll preface all of this by saying that I, like HorrorNightsFan13, don't have inside info and am just speculating for fun. For HOB Vol. 2, I could see it being Split, Get Out, and Halloween 2018, with Purge being used as transitions. Basically I'm picturing it being a movie theater during The Purge, but we see more of that movie theater atmosphere, so the first room of the maze is the theater lobby but the theater is overrun by Purgers (maybe even theater ushers/employees in Purge masks), and then we go into the different auditoriums. Since some things can't really be translated into a maze as well, maybe intro each movie with a room similar to the movie theater room in El Cucuy (i.e. for Get Out, maybe enter the auditorium/see the poster, then walk down the aisle of the auditorium while the hypnotism scene is being projected, then go behind the screen and enter the movie). The transition hallways between movies could also be continuations of the movie theater lobby/hallway with Purgers coming out of bathroom doors, etc.
Basically the idea is that it's a way to really sell the movie theater during The Purge idea that was attempted last year but lost once we entered the theater itself until the very end, which by then felt out of place. This would also be an original take on The Purge without dedicating an entire maze to The First Purge/running the risk of controversy. I know that the argument re: Split is that it's part of a larger universe with a film under Disney, but if the Split section is short and omits anything having to do with Unbreakable it could be fine (similar to how Disney can get away with having a Guardians ride by not directly mentioning Marvel). Plus with Glass coming out in January it's a way for Universal to put Split back in people's minds. With the last section being Halloween 2018, it's a way to include scenes from the trailer and not have to run the risk of spoiling anything else from the movie (as mentioned earlier by HorrorNightsFan13). Plus I agree that the new movie would probably be a bigger draw than Halloween 4, and it would be a great way to promote it. Again, this is all speculation just for fun, but a giant maze with Get Out, Halloween 2018, Split, and The Purge seems like the only way to really justify the AHS/FDTD location.
Also, this may have already been discussed/shot down, but since it's been hinted that there will be multiple 2018 horror films, is A Quiet Place a possibility? I could see it lending itself well to the Waterworld location (combination of enclosed and open air sections), and given that it's Paramount's biggest hit in quite some time and they don't have their own haunt event, I could see them wanting to capitalize on its success further. Plus it's produced by Platinum Dunes, which Universal has a bit of a relationship with for the parks already with Purge and Transformers, so that could make it easier to get as well.
