In the Marvel UK comic issue "Stargazing", Starscream claims that Christmas is a celebration of the birth of someone called "Christ". Some suggest that Christ and Jesus are one and the same—a deity, in fact—but there is no canon evidence for this.
Twitter would be the first place I'd expect to censor "consent", since getting bought out by America's favourite transphobe and serial abuser of power dynamics...
It doesn't matter whether someone is trans or nb. Imagine anyone changing their name for any reason. Let's say through marriage. Hypothetically Jane Doe changes her name to Jane Smith or something. When someone then keeps using their old last name, that's deadnaming too.
Goku doesn't consider Kakarot to be his name. He mentions that several times and some characters just don't get it. They're willfully obtuse. Goku is Goku.
Names have power. To deadname someone, regardless of why their name changed, is to strip them of the power to determine how they are referred to. It should be just as offensive to cis people as it is to trans people. I had a professor years ago who said it was akin to using slave names to destroy sense of self, its a power play, and a fucked up one at that.
I think of furries and other online friends like this, yes. Being trans isn't the only situation in which one has chosen an identity other than the one they were assigned.
That said, I wouldn't characterize Vegeta as deadnaming Goku exactly. I can't recall that Goku is upset by it, and I think it's mostly there to indicate Vegeta's continued connection to his home planet even after many years of being an Earthling.