I do agree that we all can choose what to share on HN. Usernames can be as arbitrary as you like, and not linked in any way to meatspace identity. HN allows registration and posting via VPN services. And maybe even via Tor.

However, it does appear that GDPR will require that HN delete a user's posts upon request. It might even require that HN delete posts that mention other people, including nonusers.

Edit: Yes, also via Tor. It did ask for an email address, for password resets.