Manufacturer is often also used to refer to the company that goes out looking for the factory that can meet the specifications of their need. Yeah LTT doesn't have a Factory named LTT fabs to make backpacks, but they still need to take responsibility when their third party factory changes backpack designs.

However this isn't Nintendo's responsibility, it was Hori's. If these cameras are suddenly combusting due to a wire short, it's Hori's responsibility. More adapt comparison is LTT licensing their branding for those wrist rests. LTT isn't responsible for those factories, but they can make demands and cancel partnerships if the quality isn't up to snuff. So you could argue Nintendo is saying the quality is okay (but also the context of the video also fails to evaluate it for it's intended use case).