That’s not at all how piracy works. They don’t lose any money by me not buying their product, the money was never theirs to lose. They can earn money if I buy it, but if I don’t, then nothing changed. It’s not like every company is entitled to my money.
Pirating or using Gimp or Krita instead, has the exact same effect on them, ie me not buying their product.
Regardless of the legality of the action or the product itself, a video reviewing, showing or reporting on it shouldn’t be passable of a copyright claim.
Even if the video shows copyrighted material, it still shouldn’t be allowed for Nintendo to claim it, as that would fall under fair use. Just showing a few screenshots of a video game for the purposes of education in an otherwise unrelated video would never fall under copyright infringement.
The piracy argument has nothing to do with Nintendo claiming a video as their own, despite them having no rights to do so.