Nujabes kinda popularized the genre as well. It would be weird and unnecessarily racially charged if the author referred to him as a “yellow Japanese man.”
I don't see how saying "white European" is controversial. There are Black Europeans, Asian Europeans, etc., and the author is pointing out that these channels are not run by someone from those groups.
Now to be fair, if I find any part problematic it's the "European" bit; I assumed they meant "white Europeans from western Europe," which is what that phrase connotes to me, but the vagaries of referring to an entire continent are usually best avoided, I think.