The following is a tremendously disproportionate analogy given that we’re talking about a microblogging website, but I really don’t think there’s any better term for it:

It’s really less like you’re calling Twitter by its deadname and more like you’re refusing to call it by its slave name. Twitter didn’t come up with this on its own, some guy just rolled up and said “I’m changing your name because yours isn’t cool enough.” Like, fukken Kunta Kinte.

Again, very unfortunate that that’s the only comparison that comes to mind but I’m really blanking on anything else. Jean Valjean, I guess. Maybe Darth Vader. Locutus of Borg.