Notice my headline rehashing a story from last week is just a little different than everyone else's, since they say it was leaked with a wink and a nod, probably honestly believing the studio or network released it intentionally kind of like an uncontrolled version of an early movie test screening. The reason no one would do that is obvious, there's just nothing to gain. The test screening audience has to fill out a questionnaire and so give usable feedback, while pirates don't contribute a damn thing to the equation.
So Fringeleaked out, so what? Are the 40,000 or so pirates that stole it somehow going to matter to a network that expects millions of people to show up?
Even if some metric of quality could be derrived from this nonsense, it wouldn't make any sense to do it a full two months before the show debuts. Any hype from good reviews (if you get any at all) is going to spread little and die quickly. It really seems like nothing more than a person with extremely lax ethics actively going out and hurting their employer for their own amusment, and not much more.
How many people show up in September to see Fringe will depend on how good the marketing campaign put on by Fox is, and from what I've seen so far, it won't be as many as they'd like.