They have leaked real things in the past, in exactly the same way. It may be 5% or less that turn out to be true, but there's the rub. That's why no one can completely dismiss it out of hand (and why were even discussing it on an HN comment thread in the first place).
How soon we forget that QAnon (the guy, not the movement associated with the guy) was a 4chan shitposter... and obviously all of his predictions came true :P
As a general rule, you should give very little thought to anonymous 4chan posts.