Since everything Facebook does requires consent under Article 6 (or, in some cases, Article 9) of the GDPR, what, exactly, should they do otherwise that would not violate clear proscriptions in the GDPR? This isn't a case where there is non-GDPR functionality that can be severed and provided in the absence of GDPR consent.
This kind of thing is exactly what I have been saying would happen with GDPR. Large companies will say “take all of it or leave it” - and for the most part they’ll get away with it. They have the power to do this, and very little will change for them. The difference is that they are now able to run without fear of startup competitors ever closing in on them, because no startup can get away with this same thing.
The natural effect of GDPR will be to consolidate power and data in the hands of the few companies that can both afford to comply and wield enough power in users’ lives to strong-arm them into giving consent to anything the company wants to do.