The thing is, this can't safely work on this site as it is.
As @AromanticSpices has clearly and exhaustively pointed out, with additional explanations from other posters, there are people who trawl MN to publicly out other people and they go to great lengths on some threads. I remember a couple of really high profile threads started by previously prolific posters who had been on MN for years and some people went out of their way to trollhunt them and it got so bad that the last 200 or so posts on the final thread in both cases were just trollhunters and ultimately, threads got deleted and OPs either namechanged or got banned (IDK).
An awful lot of people forget that MN is a public forum and that doesn't just mean it's open to anyone to sign up, but literally anyone can read anything posted on here. Every single discussion is searchable in Google. Every username. And literally anyone can join. Anyone with a vested interest in outing someone could use the "block" and "unblock" functions to test carefully, patiently, on anyone they wanted to target.
If they block the account, they can find people. When they block Sue's account, they block all her other usernames. They could find out that Sue, who posts in property about which house should she buy in her local area, is also Marieee, a GC feminist, and narrow down the town (or exact house, if she bought something she posted on property) she lives in.
She is also ChocolateCake1986 (her birth year) who posts on Style and Beauty. By tracing her style and beauty posts, they could find out she is blonde because she has posted on a thread about best shampoo for blondes. They can find out what coat she wears because she posted "which coat is stylish this winter?" Now they have a vague idea of what she looks like.
She also posts as PowerLiftingMum. They now know what sport she does. They can find out she does running or goes to a gym from her fitness posts. That she gardens.
She also posts as CrystalTips on the Pregnancy boards where she supports women with Hyperemesis Gravidarum or 3rd degree tears. How many women tick all of these boxes?
They now know what she looks like, what hobbies she does, and where she lives. And if they want to harm her, she is now in big trouble. Imagine her abusive ex, or a rabid TRA, or a controlling father who wants to marry her to someone back home and is ashamed of her western life, finds her and hurts her. These people have the time and patience to track her down.
If there is a way for people to follow breadcrumbs around MN to out people, some people will use it for very dangerous purposes, either to destroy their political opponents (TRAs), to ruin someone they don't like by tracking down their employer, to track down an ex who they can't control anymore, or to keep tabs on a relative they are NC with, and some of us will have to not only stop using the site and delete our accounts, but potentially ask MN to delete everything we ever posted over a number of years since we first registered. That will be a huge job for MNHQ to delete all that stuff for every person who needs to be safe.
I think the only way this would work would be if MN became a private forum where people couldn't read threads unless they were registered users with a password. And where people weren't allowed to NC without setting up a second account under another email address (which is almost impossible to police).
I don't think people realise how dangerous this thing is that they are asking for. Or they are so complacent this will never happen to them.