I dunno what he's referring to but the big changes for me for Facebook were:

1. They let non-uni students on there. Suddenly my crazy aunt was sending me a friend request and they had no option for "be polite but I don't want to have anything to do with her". That diluted the amount of stuff I wanted to see.

2. They allowed sharing posts. This just gradually turned it into shit Reddit.

Pretty sure non-uni students were allowed on Facebook way before 2014