NYT decided to dox him.

He decided that they were going to do so regardless of what he did, upended his own life to minimize the damage that'd occur when his name got released, and did so, in order to ensure that his real name and his pseudonym got linked on his own terms, not theirs.

If NYT didn't decide to dox him, the entire second paragraph wouldn't have happened.

He deserved pseudonymity for the same reason you or I deserve pseudonymity.