The number of people who're like "what's this thing about kike being a slur, I've never heard of that, so you should just shut up" would be fuckin' astonishing if it wasn't entirely expected. It's not just an American slur, the world is a big place, and sometimes stuff that's just fine and dandy where you are is sensitive somewhere else. Because everything's interconnected, just respect other people's boundaries when you find out about them. This guy shouldn't have lost his account over it, but changing the name so that it's no longer entirely identical in appearance to a common anti-Semitic slur is not even sort of unreasonable.