Before Facebook there was Friends Reunited, Bebo, MySpace, Friendster.
Facebook is the latest incarnation of Social Media.
Blockchain Social Media will work differently than traditional platforms such Facebook as it will likely be designed to reward financially as well as socially. They will also be Open Source projects rather than walled gardens. Apples to Oranges.
RE: Proposal for an incremental Constitution and Dapp layer governance on EOS