I am genuinely kind of baffled. Stranger Things is the only IP with any legitimate pull.
Trick r Treat, Monsters, and Blumhouse of Horrors (with those properties) aren't needle movers. Halloween (in whatever non-2018 incarnation) and Purge are familiar elements for the event. Poltergeist is a neat get, but I'm not convinced it has any relevant pull beyond horror fans.