Japan had 120 million people in the 80's. China is currently at 1.35 billion. There were a million new millionaires created in China in 2014. I'm not sure that the Japan situation compares to China very well.
The way things are going right now, it seems to be playing out exactly the same, just the scale is much larger given the increase in population (million of new millionaires were created in Japan also, of course, with a much smaller population base than China!).
I think the point is that if housing prices in Vancouver peak around $2M, the dust settles, and housing prices fall and equilibriate down to $1M, living in Vancouver doesn't really get any more realistic.
I too am skeptical of the Japan comparison. China is both a very densely populated but also an extremely populous country and I think its just natural that a lot of Chinese will want to leave for less-densely populated places. Just the number of people involved makes this a problem unlike any other we've seen in history; how many tens of millions of Chinese millionaires now have the option of picking up and leaving their homeland? The scale of the migration is larger but the size of west coast cities isn't; certainly not by a factor of 10.
It depends on how much is speculation vs. how much it is Chinese from the mainland actually moving to Vancouver. How many Chinese can actually emigrate to Vancouver, or why would they go there when they can go elsewhere? I'm old enough to have seen Vancouver real estate go through boom and bust before, and I'm just a Seattleite.
Anyways, we've all heard "its different this time" before, and it never is.