Bedrockgames
I post in the voice of Christopher Walken
I have to admit @Ovi is persuading me towards his usage of the phrase. If an ability as anodyne (to my eyes) as Rustic Hospitality is upending of the authority structures in the core play loop, it's hard not to see that Ovi's description of that loop is accurate. At which point the authority structure is the same as in the children's game.
Again, I think getting lost in MMI as a term isn't helpful at all. We are better off talking about the things beneath why it is being used as a term. But I would still say it isn't accurate to me because MMI is pure fiat, is orientated around binary Yes and No, and leans heavily on No. D&D includes fiat as an option, but it isn't how the GM is expected resolve every actions and the GM isn't expected to act as a thwarter in chief, but more of a facilitator of play. I don't know I've played mother may I, and I've played D&D for over 30 years, I don't really see much similarity between them. I can see how someone would feel in a moment of play, "This feels like mother may I" (just like might say "This feels like cowboys and Indians or cops and robbers). I don't think that is a very good analogy for the way authority is structured in the game. The GM is also expected to entertain players and there isn't an expectation that the leader in Mother May I is meant to entertain anyone.