Lol, you've made some assumptions there. It's not a Nintendo product. Nintendo would NEVER release any kind of flash cart themselves, as they're begging to be used for pirated games.
Everything you've said about game carts are basically why we'll never see an officially licensed product like this from Big N themselves.
With that in mind, it still makes no sense as a product because you can run games off the SD card already (I assume. Very out of touch with Switch hacks)