What is far more likely is that people will simply leave the Bay Area, and demand will fall. It's far easier to create tech clusters in other cities than it is to convince a bunch of NIMBY boomers that other people need places to live, too.
"Rent a moving truck from Las Vegas to San Jose and you'll pay about $100. In the opposite direction, the same truck will cost you 16 times that, or nearly $2,000."
https://www.sfgate.com/expensive-san-francisco/article/U-Hau...
Short of a bubble popping, it usually doesnt work like a cusp, but rather, things remain on the edge of extremity (i.e.: dual income couple plowing 70% of income into insane mortgage.)
Wouldn't it have been done by now if that were the case? Yet SF is still the Mecca for the tech and startup scenes.
It's easy to see every major tech company having a base in SFBA for the foreseeable future, but it's also easy to see being a working programmer living in one of those smaller markets and actually being a homeowner being a much bigger thing going forward.
And while those other cities do have some tech scene, it's still nowhere near that of SV, and that's still the first choice of most developers.