The article fails to mention it is an average, so IF we are lucky, it may happen tomorrow, and if not it may happen much later. That also depends on the definition of "lucky" in this case: if they answer by zapping us the Mars Attacks way, I wouldn't call that "luck"
It also doesn't take into account that we may receive a signal from aliens regardless of whether we sent a signal ourselves. After all, we may as well be on the other side of the equation, being the aliens answering the signal.
In short, this is a long article to say that we actually don't know and should expect a long time

The real sign that someone has become a fanatic is that he completely loses his sense of humor about some important facet of his life. When humor goes, it means he's lost his perspective.
Wedge Antilles
Star Wars - Exile