As far as I can tell, there’s still no way for members to delete their own accounts without contacting the site staff, and as you can see in the screenshot below, the comments remain when you delete a member, but the member name is replaced with Deleted member.
I’m ok with the comments remaining since the user name is no longer visible and it avoids “plot holes” in the conversation, but in the end it’s up to the member to decide if they’re ok with that. I’d sure like for members to be able to delete their own accounts as it keeps the member in control of their own data and obviously lessens the burden of the staff of the site.