5000 new jobs is not what the article is saying, but capacity to grow to 5000. I don't know how many they have now, and creating capacity to do something is not the same as actually doing it. Also, to put the number in perspective: 5000 would be only 4.3% of their global workforce, and my guess would be that Canada must actually be one of their biggest non-U.S. presences. (London also has a strong one for Google).

I'm also not saying that there's anything wrong with these companies expanding their presences outside the valley. (I would very much welcome it), only that we're not seeing enough of it right now to contradict the notion that these companies are still very much centralized. Maybe real estate prices and competition for tech talent will eventually force them to properly decentralize. But I could also see a scenario where those companies could put their might into play to overcome that resistance-level and allow them to continue growing while remaining centralized. It's simply too early to tell which way this thing is playing out.