Going back to the "racial insensitivity" accusation, one of the things that's utterly bizarre about it is that the complaint about Cho Chang's name is so off base it's actually painful. For one thing, those spellings aren't Chinese OR Korean, because they are using anglicised letters - they are always going to be an approximation of Chinese sounds.
"Chang" is an anglicised version of a Chinese surname, the character for which can be seen here along with other, alternate Western spellings:
en.wikipedia.org/wiki/Chang_(surname)#:~:text=It%20was%20listed%2080th%20among,as%20%E7%AB%A0%20in%20both%20systems
It can also work as a Western spelling of a Korean surname (Jang), but just because Westerners use the same spelling for a surname in two different East Asian languages doesn't mean that one language cancels the other out!
"Cho" is also a Chinese surname, and is usually the Western alphabet transliteration of the Cantonese form of Cao:
en.wikipedia.org/wiki/Cao_(Chinese_surname)#:~:text=Cao%20is%20romanized%20as%20Ts,it%20is%20now%20written%20T%C3%A0o.
Where things get really interesting is that the Chinese given name "Qiu" does sound a lot like "Cho" to an Engish-speaking ear. In Chinese editions of Harry Potter, the character's name is written as "Zhang Qiu" (張秋). That may not have been intended by Rowling, but it hasn't taken a massive effort to produce a feasible Chinese name in Chinese out of Cho Chang.
So, at the absolute worst Rowling may have unthinkingly given her character two surnames, or she gave her an unusual transliteration of Qiu. If that's "racist" if your world, you're pretty sheltered!