> By admitting a mistake, the poster stops the runaway train of replies and amplifications of their mistake, and the reputation damage that follows. No matter the apology of the mistake, those who demand them to apologise will still reject it and push further for calls for the accused to be cancelled. The replies and amplifications will divert into real life instead of Twitter.
I think we can distinguish apologies into two top-level categories: meaningful and meaningless. Meaningless apologies can be further subdivided ("I'm sorry you were offended", or "It's just my culture to be a jerk"), but I'm not interested in that - they're all meaningless. Meaningful apologies can be easily found via the search engine of your choice, "How to apologize" brings up lots of hits. The thing they all have…
One of the things I think about most in design, especially in design of social products, is limiting self-sabotage. This is because there's really significant emotional risk in social systems of feelings like being exposed, misunderstood, etc.
This is why I favored the approach of not including a Follow-up or further explanations. It makes the choice Mea Culpa very simple, favoring cooling off of conflict over continued debate. Basically people can go back in their corners and think about things, and figure out how to approach things again later if they choose. It is an intentional choice to favor respectful debate over maximal information exchange, acknowledging the medium's tendency to escalate conflict and the presence of many bad faith actors.
Also note this feature does not take the place of the apologies you're talking about, it just offers an acknowledgment of mistake and an opportunity to forgive.