Bob Garfield's initial pessimism about Facebook as Publishing's savior has come to fruition in FB's new algorithm.  Bob's most recent editorial in MediaPost cites devastating numbers relating to a drop in engagement with publisher content on FB, causing Facebook to re-evaluate how it serves its audience.
Bob does offer a sliver of a silver lining, but it depends upon publishers to offer content that is shareable, or popular vs. Pulitzer-worthy.