As Russ notes, this is the second strike from Nintendo on his channel. The first, it's worth pointing out, was related to his coverage of a device which allows you to dump Switch games to your computer
[My emphasis]
It should be noted, the only way to legally play an emulated game is to dump the files off a cart/cd/floppy/w.e that you personally own. Which makes this even more egregious, as the video is about a device that could be used for piracy, but is also one of the only ways to legally make a backup of your property.