YouTuber OBE1Plays revealed that the new Assassin's Creed title, rumored to be coming out next year - would be releasing day-one on all three major consoles. This includes the Nintendo Switch.
This is reminiscent of the Wii U generation, as Ubisoft adequately supported the console with many ports that came around the same release as the other consoles (save for Watch Dogs, which released on the Wii U quite a while after other platforms). Also, this lines up with the enthusiasm from Ubisoft that's been resonating around the Switch.
If you question the validity of OBE1Plays, Laura Kate Dale (who's been known for releasing very founded information regarding the Switch) backs him up with her own sources.
As for now, there's been no official word from Nintendo or Ubisoft. Here's to hoping they confirm something around January.