“Cho and Chang are both last names. They are both Korean last names. I am supposed to be Chinese. Me being named “Cho Chang” is like a Frenchman being named “Garcia Sanchez.”
Apparently some Asian people got pissed because Cho Chang could “technically” be a Chinese first and last name. Rostad later stated in a comprehensive response that she knew, but sacrificed the details for a punchline.
Whatever criticism of racial stereotypes aside, Cho Chang is still a pretty shitty character and a pretty stupid name.
(As far as I know, no Chinese person romanizes Qiu as “Cho.” A more extreme analogy would be like spelling Hussein “Hoosayne.”)