This is a (quite) question of #openweb vs #closedweb
The Fediverse worked/s because it is #4opens at a protocol and #UX implementation, it’s a #openweb project, this is a good thing. Yes, the is a history of well worded “white lies” about privacy and safety that have helped to change social behavers. A kinda not bad thing.
One of the #4opens is #opendata, every post has a URL, the is no encryption at all, in this all “privacy” is based on trust, a good thing.
I agree with the need for #openlicence for content, it’s one of the #4opens, a good thing.
Where I worry, a little, is some people seeing this (often unthinkingly) as an opertunerty to push #closedweb thinking into a #openweb project. This is a small problem that is good to keep an eye on 
My though is to set a permissive CC content licence as default (the power of default) and let users change this to completely open or a more restricted licence, then “trust” coders/people to respect this.