I feel like we would have got this on Mario Day if it was coming. Sorry dude, they're surely on to Wonder 2 or Maker 3 on Switch 2.
Throwing some more shit out there-
Fantasian (Apple Arcade exclusive made by original Final Fantasy creator) had a steam listing discovered and NtH says that its multiplat release is getting revealed tomorrow. That has to be at, at least, the Japanese Direct, right? Word of mouth is that the game was pretty good but dying on the vine in the 2024 version of Apple Arcade.
Pyoro, who has been unusually quiet about this direct (he usually gives most of the games, even first party ones, but in the form of homosexual hints and other attention baiting) and now says that it is going to be light on first party stuff. Seems to hint that Mario Party is on the way.