As much as I know Nintendo would love to sell the same games again, I doubt they’d rather put in the time and effort to port the most popular games than put that effort towards being able to continue selling the Switch’s pre-existing back catalog on the new system.
edit: However, I can definitely see them doing the PS5 thing and charging $10 to upgrade Switch 1 games to take advantage of the Switch 2.
You still can’t get Rocket League on Steam on an account that didn’t already have the game bought before it was F2P. Is this the case for Fall Guys, or did they go further and stop updating the Steam version?