While [0] doesn't come across as GDPR-compatible to me (not a lawyer), the further explanation in [1] sounds a lot more compatible with it.
Basically, HN will work with a requester to update the site to give the desired amount of anonymity whilst preserving history as much as possible with those limitations -- including editing past comments.
Full GDPR compatability would probably require to support complete removal of user name and comment/submission contents as written - but even that seems on the table in [1]. (DanG could simply summarise each comment worth multiple replies and delete all the ones without replies.)
Basically, HN will work with a requester to update the site to give the desired amount of anonymity whilst preserving history as much as possible with those limitations -- including editing past comments.
Full GDPR compatability would probably require to support complete removal of user name and comment/submission contents as written - but even that seems on the table in [1]. (DanG could simply summarise each comment worth multiple replies and delete all the ones without replies.)