Many users no longer feel safe participating here and don't feel comfortable with SE having data about them. While there is a way to delete your account which will result in all your posts being dissociated and your username replaced with a generic "userNNNN", that isn't enough.
Your old username will still be visible in comment mentions (@terdon) and can still be found in answers ("As terdon mention in their answer...", linking to the now dissociated answer). This means that users, and especially those who have chosen to participate using their real name, are still not safe.
If someone has been made a target for trolls, deleting their account won't help them. Their real name will still be visible in the comments, or in other answers. They will still be targets. Given the current extremely tense situation, this is a far greater danger than it used to be. It is essential that SE give folks a way to entirely remove themselves from these sites.
I am not a lawyer, but I understand there may also be a legal obligation to do this, at least for people affected by the GDPR. Deleting my data should include deleting all mentions of my name that can link me to my activity on the network.
But whether there is a legal obligation or not, there is clearly a moral one. The current situation means that this network has put its users in danger, so it should provide a way for those users to protect themselves.
So, please provide us with a way to completely remove all signs of a user's presence on this site. I understand the technical challenges in this, and it may even need to be a manual process, but this needs to be done. Or at least done better than it is at the moment where it is trivial to find out the original username in a page where there have been multiple comments.
One thing that shouldn't be too hard to implement and would go a long way towards addressing this issue, is to focus on pages the deleted user has been active on. So, if user Jon has posted an answer, and Jon is now user123 because they've deleted their account, then all mentions of
@jon in the comments should be changed to
Yes, that might mean some other Jons are affected and their name erroneously changed, but that is the lesser of two evils and a small price to pay to make the real Jon safe again. The good news is that even in cases of exceedingly common usernames like Jon, chances are that most mentions will be of the relevant one since it is less likely (although far from impossible) that two completely separate Jons have interacted with the same post.
Alternatively, remove all Jons where there has clearly been only one user with that name, and flag the harder cases for manual review. Then a human can read through them and figure out which to delete.
Finally, even if this isn't perfect and still lets some mentions falls through the cracks, that would still be a significant improvement over what we currently have. Dissociating a post from its author but leaving dozens of comments that refer to the author with their original name is a band aid. Any improvement would be a step in the right direction.