From my understanding, even though they both run Nvidia-designed ARM processors - there are enough differences between the two SOCs that a direct 1:1 translation is not possible for all titles, and those will need to go through an emulation layer.
Additionally, there are certain titles won’t be compatible due to hardware changes (Ring Fit Adventure for example, and probably all of the LABO stuff?).
From my understanding, even though they both run Nvidia-designed ARM processors - there are enough differences between the two SOCs that a direct 1:1 translation is not possible for all titles, and those will need to go through an emulation layer.
Additionally, there are certain titles won’t be compatible due to hardware changes (Ring Fit Adventure for example, and probably all of the LABO stuff?).
For Ring Fit and Labo, they’ve clarified that those games aren’t compatible with new JoyCons but can still be played with old JoyCons.