As much as I appreciate the sheer balls of this, it's clearly not in compliance with the law according to the recitals; consent gained in this fashion is not "freely given." Now personally, I think this approach should be acceptable -- if you don't like it, don't use it. But under the GDPR, that's not the deal. Be right back, making popcorn.
I think it's debatable. Yes, if they were denying service unrelated to the consent, that would not be freely given, but everything Facebook does with your account is covered by GDPR, and there doesn't seem to be a clear and explicit rule on the required degree of granularity of consent when multiple functions all require consent.
I actually think this approach might be the safest thing FB can do regarding GDPR other than unilaterally and without recourse dumping every account of a person protected by the GDPR, perhaps while developing a completely new system with a different fundamental design and business model for the EU.