The Outer Worlds created a momentum, Nintendo Switch keeps a momentum and now these two collide.
early at 2020
As far as we know today, The Outer Worlds for Switch will not have any additional content for the platform. And that's perfectly fine, the game is fantastic as it is and the reason is to just be available to more players.
I played and finished the main game and most of side-stories. If you are a sci-fi RPG fan, I recommend you to purchase the game and play it anywhere you want or can.