I mean couldn't they just drain the lagoon and put a tent up there?
9 haunts would suck for crowds, but if that means they all get a budget increase (doubtful), I won't complain too much. I'm guessing the rest of B-108 isn't able to be reconfigured to allow for another haunt, but maybe with some clever queue re-routes that I don't have the energy to brainstorm currently, SS21 (Hellblock + Bloodmoon queue side) could be utilized for a haunt instead.
Also, after seeing the trailer again on the big screen, I'm all-for an Abigail haunt.