London has said that he deep-down recognises that he isn't actually Korean, he admits to some degree that it is a pretend as a result of a strong interest, maybe even may I say, an unhealthy obsession, with a Korean pop band and the Korean culture (though, like Rachael Dolezal, I suspect there is more to it than that).
I can understand why people find this offensive, (I find it offensive in a cultural appropriation kind of way, mostly I find it disturbing that he is lying to himself so effectively and others are enabling his delusions) though I don't think anyone should receive death threats, he does show some kind of understanding of reality, he has just chosen not to live in it.
Is he moving there so to fully engage in the culture or just having surgery?