This might be a problem for one or two of the top areas, but there are not enough Bay Area emigres to materially move the needle in the vast majority of non-Bay Area localities.
Try "tens to twenties of 'top areas'". Just look at the housing market in any other city in the US that's started to build a tech hub. Austin, TX in particular is a good example where the average cost of a decent house has basically doubled in the last 10 years.