WARNING: Verify!!!
For existing Facebook users, test using 'Download your Data'.
Facebook recently added beacon images into the download (sneaky). Check those against the Hosts file above. For example, mine are not blocked by this list. Which is also the problem here.
Hosts file lists etc, need to be updated regularly, just like legislation. Otherwise we're all playing catch-up with an enemy that is faster and nimbler than you or I can ever be:
https://forums.theregister.co.uk/forum/1/2018/04/18/facebook_privacy_settings/#c_3489424