From what I have heard (And what HHNRumors is hinting at) is that the Blumhouse of Horrors will consist of Sinister, Ouija, and Insidious and their Sequels. While Get Out was mentioned by "The Ifrit" it was never mentioned by my Source nor "HHNRumors".
As for Announcements Hollywood will have their tickets go on tommorow so I wouldn't be surprised if you got a Blumhouse announcement tommorow and then a Jigsaw Announcement and full lineup reveal on August 3rd.
Aaaaand there goes my hype for the house. Not having Get Out and Split is a crime.Also, by the way, the code name for Blumhouse is "Numb" if you want an indicator of A&D's excitement level for this.