Yes, I think he's distinguishing between season tickets purchasers, and season tickets. For example, I'm one purchaser with four tickets. So the 11,000 tickets available are purchased by a much smaller number of individuals. I think 6,000 is actually pretty generous, since that would imply a lot of season ticket holders are planning to purchase just one ticket this year (since a lot of season ticket purchasers, like myself, are buying more than two). How many people do you know that come to games by themselves? Not many.
One thing that's going to really piss us all off, though, is if the "usual suspect" season ticket holders purchase tickets but don't attend. There's always a healthy number of season tickets that don't get scanned every game. Needs to be some really easy way to move those on to other fans to make sure we've got as close to the 11,000 in at each game as possible.