From a legal standpoint, I don't think it makes a lot of difference. Especially since unless you are specifically trying to make a throwaway, figuring out who you are is trivial, especially if you use a chunk of your RL name in your username. Or in my case, if your username is commonly identifiable as you and tied to your RL name on other sites.
I don't think anything about Right To Be Forgotten leaves it to the individual's responsibility to mask their identity.
From a legal standpoint, HN doesn't sell products, use user data for profit, or operate in the EU. Both it and YC have made it rather clear they don't want to touch the EU.
Complying with GDPR would basically be an act of goodwill more than anything, and even that's debatable.
Unless they IP ban the whole of the EU, they will still be subject to the GDPR once any EU citizen accesses their site. (Which, agreeing with AmericanChopper, is a purely theoretical thing - until the moment where YC wants to conduct any kind of business in the EU)
If they raise money from any limited partners in the EU it’s pretty easy to make a case they have an EU business. The physical location is irrelevant - that’s the whole point of the GDPR.
I think you mean from an enforceability standpoint. From a legal standpoint, GDPR applies to all EU ‘data subjects’, and HN would be in breach of it if they don’t provide EU ‘data subjects’ with their rights under the GDPR.