Agreed, explicit is almost exactly opposite from the truth for owners. I guess if you're a hardware implementer and poke around you'll find people saying it's not USB-C, but that's not in any way Nintendo being explicit. Why they might have been explicit about would be to never use anything that wasn't Nintendo branded at a major markeup. After the last few decades of profiteering a lot of users have been trained to assume that the only reason is money.