> This is how this is supposed to work in a healthy and well-functioning society/community -- it moderates itself with internal deliberation about what the norms are and with reflection and awareness of how things are changing, with self-assigned community leaders and adults!

I'd like to think that it's a good idea, but don't you think that it will quickly become an echo chamber?

Think of current communities known for being intolerant of outside ideas (The very religious communities, the hard left/right communities) - the only way they can do so is because they police themselves against new ideas.