Looks like a seed of the Current Year BS of "cultural appropriation" is the notion of "indigenous intellectual property".
Some "indigenous peoples" - likely tribal officials or lawyers living in the modern world - think that ways of "indigenous peoples" should always be "intellectual property" of certain peoples. They think "indigenous intellectual property" somehow "protects" those ways, and it also seems they think "customary laws" about such ways applies beyond their tribes. In 2002, some worldwide convention even claimed that the "unauthorized use" and "misappropriation" of "traditional knowledge" is "theft".
Such delusion supports the idea of permanent "intellectual property", and tries to rigidly or artificially pigeonhole certain ways. It also seems to subtly support The Narrative™ that one of a kind deemed "oppressor" is automatically responsible for the actions of others of their kind. And it also ignores that tribes likely copied "traditional knowledge" from each other throughout history - and of course that information itself is not like physical property: copying doesn't reduce it. I also doubt the notion of "indigenous intellectual property" existed before the modern world, and likely isn't a thing with "indigenous peoples" outside civilization.
