Actually, that's not a 100% thing. I could wake up tomorrow, trip on the stairs down because I was sleepy, fall all the way down them, hit the landing and snap my neck. I might even cross the street today and get hit bay a car. Boom, lights out.
Just because someone is old, doesn't mean you'll outlive them. In fact, I'm sure if you looked at statistics, there's more young people dying before they hit their 20s and 30's then there are withered and ancient old folks. The simple idea that you'll outlive somebody simply because they are old, is rather silly, when in fact life can throw you a fastball at [i]any[/i] time.
Yes, most likely, Gabe Newell will die in the majority of people's lifetimes that visit this place. But not for all of them, because chances are, a fair number of them will die first.
So change your title. Gabe Newell might die in your lifetime.