I called NW to verify this info, and got a Seattle agent. They said they don't book this award, only the RTW desk does. No award rules that she could tell me. I've had agents tell me this before, and were incorrect, but I will try to call when the RTW desk is open to clarify this issue.
If true, it's a serious hit the one of the best awards that NW has. Let's hope that it's just confusion on a NW agents part.