Assertions are not evidence. A government declassifying itself making an unsubstantiated assertion is not "declassifying" anything. This is not the sort of behavior anyone would accept from anyone else, except perhaps a televangelist or a cult leader.

If I got on here for example and began drumming up publicity with claims that I have evidence that extraterrestrials are visiting this planet, and then after racking up millions of views and lots of publicity my evidence turned out to be a video clip of me saying "Extraterrestrials have been visiting this planet," I would be called a liar, a scammer, and a clickbait grifter, and rightly so. I could then claim that I can't provide any further evidence beyond my own assertion without compromising my sensitive sources and methods, but I'd still quite rightly be called a liar, a scammer, and a clickbait grifter.

But if I'm the most powerful institution in the world and have an extensive history of lying about exactly the sort of claim I just made, that's considered fine and normal within the mainstream western orthodoxy.

Reading by Tim Foley.