IMO It was mostly leaked information (therefore unreliable) and conjecture. Much of it was put out by a biased Boulder individuals to appear that they knew what they were doing.....Otherwise known as "saving their B__ts"
I agree with you regarding the evidence against the Ramseys. But I was referring to basic knowledge of the house, the staircase, the bonus check's exact amount, where it was, etc., the stuff that JMK was supposedly privy to. All of that was public knowledge years ago so I don't see what JMK knew, at least from the linked news article, that was restricted from the public domain.
Maybe we'll hear something soon about information specific to the crime scene itself, but for now I'm just hearing that he has knowledge of stuff that has been public, albeit not widely circulated, for years. If he was obsessed with the case and planning to write a book on it, I don't think it would be that hard to research it, interview key people and find out "details of the basement", for example.