From what I've seen, that seems to be the only thing (besides Potter) that would open in the next year.
If that ends up being the project he's referring to, it might be something more than we think (which could be why it's been kept under wraps). I remember seeing a post a while ago about a Walking Dead-themed shooting game (similar to Infected at Knotts or Biohazard at USJ). Maybe it's that (or something along those lines)?
I know it seems unlikely, but I can't think of any other area in the park that would be opening an attraction of some sort in the next year. I also remember Murdy tweeting a while back (after HoH closed) about something cool replacing it that he couldn't talk about. I can't remember what he said specifically, though.