How would this penalize you?
The end result (as I'm imagining it) would be that these new national-average tech salaries can still provide a very comfortable living in low-COL areas, but are no longer comfortable in high-COL areas.
Realize with areas like SV you're also competing because of desirability not related to job market. If you want to live in certain parts of CA it's going to cost more.
If what you are worried about does happen I suspect it would take on the order of a decade to show up. But regardless of timespan, I must say I don't care. Your post is just crocodile tears.