They used to constantly talking about race was bad because you're basically insulting someone on something they didn't choose and can't change. Naturally that upsets them.

If someone says you're a jerk because you're, say, a lawyer - you chose to be a lawyer, and if you really hated it you could stop being a lawyer. You might be angry but it's not the same identity-level anger of being something that's impossible to change.

Here they literally created a new group with immutable characteristics. I mean they weren't immutable to start but they've immutable after the surgery. They're stuck in a broken body forever and don't want to be alone so they desperately want to create more people like themselves.

They literally created a new group with "immutable characteristics".