Truth right here. The reason we know about some of the things they'll show is because we discussed to hell and back every tweet, every retweet, every teaser, people have been checking board ratings, achievement lists, acquisition papers, job listings, APIs, etc.. In this day and age it's so damn difficult to work on a game for years without as much a hint going out between ex-devs, APIs, job listings, external companies accidentally leaking something, a voice actor not knowing when it's time to shut up, etc. etc.. One can avoid all this by... ignoring speculation and rumor threads :P
It's kinda like sneaking in to a movie shoot, getting a sneak peek at the final scene, then complaining you already knew how the movie ends. I mean, you literally went there to know about it, so...