> that seems like the exact same usage as here: tying a pseudonym to an IRL for purposes of law enforcement.

I disagree. Tying a pseudonym to an IRL persona for purposes of law enforcement is a part of an official investigation.

Doxxing is specifically non-government unmasking and dissemination of that tie for extrajudicial purposes, almost always for harassment. There is a world of difference between them and we should not fudge them together with terminology. My 2c.

What if the government reveals the name of a victim of sexual assault? Is that doxxing? What about a political rival in connection with a made up crime? What about a true but benign crime such as accessing reproductive healthcare?