Gabe's quote is right there on the blog of the first link:
Do they even know the game? I guess they must've had early access or that would be a stupid tourney.
“The International is the first public Dota 2 event and will give the tens of millions of gamers playing Dota around the world their first look at the new game,” said Gabe Newell, president and founder of Valve. “I have had the good fortune to watch the competitors as they prepare for the tournament, and the level of play is extraordinary.”
The top teams are pretty much the beta testers for the game.