No.
What your describing already has a term, it's called whitewashing and rewriting history. And even if you were to apply that here it would still be a reach
The problem with your use of "the them" and "us" is you're giving individuals like dumbass gossip bloggers and cosmetic journalists authority as historians. In what school are you being taught white people invented dreads or rap music? I've known jazz blues and rock were invented by black folks in middle school. The bolded is all emotion and like I said the cultural appropriation argument existing in a black vs white vacuum.
And yes, as an american appropriation of other cultures is part of our culture, there is no escaping it. I mean Cinco De Mayo celebrates an event Mexico barely commemorates, even commonly miscategorized by us americans as Mexican Independence day. It's the best example of cultural appropriation even by your definition and nikkas still celebrate. It's part of being a globalist society so it really isn't that bad. But it's still appropriation
Furthermore you used the most and probably only logical example of people calling out cultural appropriation. If it was about whitewashing that would be one thing but the majority of the time this discussion is had over white boys wearing durags, white girls getting fake asses or white people being ignorant. Majority of the time nikkas is crying about shyt like this