I liked that take (I think it was from the Gauntlet Podcast) that if a PbtA game didn't have a catch-all move, it was actually an statement.
Like, "this game doesn't want you to roll anything if it's not covered by the other Moves. Just solve it in the conversation. This game/genre/setting DOES NOT care for that thing you think you should be rolling for. Seriously, just decide if it works or not without a mechanic. You'll be fine." (paraphrasing, but you get the idea).
It made me think about why we roll or instinctively expect an action-resolution mechanic for everything, probably a leftover from trad games. Maybe in some PbtAs it's not necessary? I'm still undecided on the matter, though.