Honestly, if Blumhouse return, I would think that it would be a shared house, and would contain two shared IPs and one original for each.
I would agree that it would make sense that Happy Death Day comes to Orlando, but I would think Hollywood would get something else to fill that hole (as it was used this year for Hollywood).
I would think Purge and Halloween would come for obvious reasons, and it wouldn't even be that bad of an inclusion if both are given their due in the mashup.
To diverge, I have to wonder if they may not have an official Icon this year, but I'd love myself to be proven wrong in that.