Not sure of what conspiracies you’re thinking of, but if actual evidence was leaked, then we are talking about a clear failure of those involved, therefore this is evidence for the claim that large scale conspiracies are indeed impossible ;-)

You can believe what you want of course, but from my POV when the discussion ends up in non-falsifiability land, you might as well talk about the existence of God or Santa Claus, an interesting discussion for sure, but not one that can yield any useful insight.