You obviously haven't been in the real estate market in an area that is "hot" right now. I get calls every day by real estate agents looking for houses as they have more buyers than sellers, especially here in the Bay Area. They have the listing of the house due to the last time it was refinanced, so they have the ball park of how much the house is worth given the recent sales in the area. So they have buyers ready with money if I'm willing to sell, all I have to do is sign. All my neighbors are getting the same offers, again none are willing to sell.
Despite your claims of a mass exodus up here there are still more people coming in. This is because even though some long established companies are changing the address of their HQ, their workers are still here and are not requiring them to move. And are bringing more workers from all over to fill positions. Not only that but VCs are still funding new start-ups right here in the Bay Area. The Bay Area has had a house shortage for decades, and its not going to magically get resolved because "some" are leaving.