I’m still curious about the possibility of Penny Nichols-style games where ceding control to the LLM (for the sake of accommodating literally any player input) is the point, but I suspect that if there is a non-slop application for AI in IF then it’s going to be some kind of one-size-fits-all layer that translates invalid but sensible commands into something the parser understands. I imagine something much like @Draconis suggests, but with the inferred command actually carried out so newcomers don’t have to retype the “correct” version.
An AI-friendly comp might help arrive at or improve such a system, and early efforts might benefit significantly from the game itself being designed to make its task as easy as possible, but my feeling is that this sort of thing would ultimately make more sense as an extension of sorts than a game: the best possible version of it could be bolted onto just about anything, and wouldn’t necessarily make sense as something to be judged as a competition entry.