To allow users to build their own communities, let them set Tags on themselves from a curated list. These tags could then be leveraged to filter for user visibility/voice (without being Friends). This would allow users to only connect with those that share some common Tag (or set of tags)

The first one I would propose is "Adult", in order to weed out all the children abusing the CoC. This method is a second step to let users establish their "age". The first being the date of birth set when you signup. As most kids lie about their age just so they can have their voice heard, I don't think they will bother with abusing this specific Tag very much.

If users abuse a tag, others can report them for such. This tag addresses the debacle of kids abusing accounts, and teenagers who also aren't very mature from annoying older more mature (hence Adult) players. I don't care that the term has grey areas, it would vastly improve the situation for adults.

I'm sure tags like Country, Language or Region might be of value to many as well.