A double-negative is not the same as a positive - but the result may be a close approximation; or essentially very similar.
So, when the Establishment (i.e. 'Them' = governments, large corporations and institutions, or the mass media) label something as 'fake news' - and when these organisations are all themselves essentially fake and fundamentally dishonest - then we have the phoneomenon of Fake-Fake News.
Fake-Fake News =
Accusation of Fake News, from a Fake source
How should we regard Fake-Fake news? - When a major global/ powerful/ wealthy/ influential entity starkly announces that X Is Fake (and, implicitly, therefore needs to be suppressed)?
We should, I suggest, regard it as - if not exactly 'true', because truth is seldom/ never known (especially not by these groups) - something this group believes to be essentially correct or to contain an important but unwanted fact.
Fake-Fake News = Some-thing They believe to be true.