[divingdragon]

> They did this to micro sd cards on the first switch.

What do you mean? From what I know it was bog-standard microSD(HC/XC) with the maximum supported speed being UHS-I with nothing proprietary.

[ninjatendo]

It's more nuanced than that. The nintendo software prevents things, like save games, being saved at places which it deems unworthy.

[vel0city]

But that's not something with only approved microSD cards work with save games. The Switch will not write save game data to any microSD card, regardless of features/manufacturer/branding/royalty payments/whatever. It's just not a supported feature, at all.

The GGP comment makes it sound like Nintendo only supported proprietary microSD cards at launch. While they did sell and recommend their branded microSD cards, one could use any brand of microSD card with the system and have the same functionality.