From the interview: "I've learned in the past you need to be careful announcing things before they're ready, because sometimes you have to cancel them because they don't work out. We could work on an expansion and it could be boring, and we should stop working on it. Because if we would continue on something that's boring, we would then have to sell it to you, and then we'd have to say 'here's a boring thing, and we want you to buy it.' That would not be cool. So we have to have the freedom to experiment and do our stuff. And then when we're ready to announce it we will."
I wish more game studios took this to heart.