Does HN have to care about a GDPR request? HN doesn't have either servers or people in Europe, so far as I know.
Even so, that still may not save you. Say you decide you want your post here deleted. Say HN does so, but leaves my reply. And say my reply looks like this:
> We'll see about that the minute someone makes a GDPR request to delete their stuff.
Well, Paul-Craft, I don't think it's going to work like that...
[End of pretend reply.]
Now your post is quoted by mine, and your name is mentioned in mine as the author. Now you cannot delete all traces of your post without editing mine.
Now what?