If there was less demand for expensive areas, the market would adjust and they would become less expensive. The overall effect would be an averaging effect on real estate prices as cheaper areas became more expensive and expensive areas cheaper.
But it seems quite possible that incomes could fall faster than demand given there are other factors influencing demand like foreign buyers. And the money saved by employers would make many already rich people significantly richer. Perhaps the nice areas of the country would just become a playground for the rich (more so than they already are) while everyone else is in dystopian exurbs and suburbs.
