Ringwraith can correct me if I'm wrong, but I assumed "meta" was specific to UOR/HHN, not necessarily meta in and of itself (tho my speculation is both).
So ...
- "Big" IP (not music)
- Horror-adjacent at best
- Meta to the event
- Polarizing to HHN fans (90% of time translates as "not perceived as scary/gory enough")
Since Legacy mentioned some seemingly unobtainable IPs, let's go with one that hits all four of these: Simpsons Treehouse of Terror. Initially seems far-fetched, but if the team was in negotiations about Springfield anyway, maybe an unthinkable deal was struck. Money talks.