If all deleted accounts' usernames were replaced with "[deleted]", that would hypothetically do a pretty decent job of defeating text analysis techniques. A single post isn't really enough to characterize someone's writing style, and a sufficiently large pool of deleted accounts would make it quite difficult to reliably pick individuals out of the slush pile and group their comments together.
That said, HN is being archived and mirrored in I-don't-know-how-many-places, and I'm not sure how feasible it is to track all those places down and get them to expunge your userid, too. And this is all assuming nobody comes up with a new de-anonymization technique that deals with it well. That is a rather big assumption considering new ones are being developed all the time.
I imagine the same analysis can be performed on other networks like reddit, twitter, github, linkedin etc to find matches amongst them all, [deleted] is a signal as well. If there’s a strong match across one or more of those and a deleted one here, or vice verse to rule out possible matches, and the others are not anonymized [well enough], then it could probably deanonymonize quite a few deleted accounts here.
I’m sure something like this is available to recruiters or other HR/business admin, I remember seeing browser extensions/SaaSes years ago that were trying to tie together social media identities.
That said, HN is being archived and mirrored in I-don't-know-how-many-places, and I'm not sure how feasible it is to track all those places down and get them to expunge your userid, too. And this is all assuming nobody comes up with a new de-anonymization technique that deals with it well. That is a rather big assumption considering new ones are being developed all the time.