Whats happening in real i think is that EU realized it will never be able to chop Google or Facebook in pieces so they make it harder for these companies to exist on local market. At the end of the day free market still rules in Europe - if Facebook disappears their hole will be quickly filled in with 20 other social networks “made in European Union”.
EU laws already cover EU companies as a matter of domicile. GPDR only applies the rules of service delivery already present in EU. EU service delivery rules say that a service is delivery point is considered the place where the service consumer is, not where the provider is domiciled.
YouTube regularly blocks fair-use videos (remixes, criticism, etc) because the automated filter finds something that matches and can't recognize context.
Google regularly gets DMCA takedown requests for search results that go to official websites and YouTube ads/trailers.
My Facebook feed is covered with old acquaintances sharing news links and other such content.
It seems like it would be really easy for Facebook to run afoul of this, just due to others' incompetence.