Legacy over on Horror Night Nightmares actually had a pretty good theory as to why we aren't getting announcements...
Freddy vs. Jason is pretty clearly their flagship property to tout for marketing this year, along with Jack as the "icon." Why reveal Walking Dead, Insidious, or Scream early, since it'll just confuse the message?
Don't know if I entirely agree with Marketing's strategy, but this appears to be their move.