I think the wholesale abolition of identity is probably too unpopular to be viable, and that the goal is accomplished with a sufficient reduction of identity. What counts as sufficient is anyone's guess, and probably too important to be left up to guesses, but I suspect that not allowing you to link an actual identity to the thing sufficiently dampens trust as to be sufficient.
If all you're risking is your karma by being outed as a deceiver, that's probably not enough for someone to trust that this is sufficient incentive to keep you honest. By extension, they no longer trust what you write.
That said, what you mean by untagged is what I meant by anonymous.
It's a tough nut to crack. There is genuine utility in being able to follow the respondents in a thread like this. I'm responding to u/ouid but will the next reply to this be from u/ouid or someone new who hasn't been a part of the conversation until now? This alters the dynamic of how the conversation continues to flow.
Of course, once you place a tag of any kind on someone's posts, you can begin to build a profile that destroys any anonimity. Perhaps a randomly generated number that persists in this article's comments but resets to something new on the next one? That gets unwieldy in a hurry and probably still allows the site operator to build a profile.
If all you're risking is your karma by being outed as a deceiver, that's probably not enough for someone to trust that this is sufficient incentive to keep you honest. By extension, they no longer trust what you write.
That said, what you mean by untagged is what I meant by anonymous.