No. They won't. This isn't anything new. GitLab as a company does this. My company does this. US Federal Government does this. It's not controversial. HN is the one making it controversial. YOU are making it controversial by bringing race into it.
If you have clear salary bands ("SWE III makes base 100k to 150k") and clear location bands ("NYC is 35%, Westchester County is 29%, Monroe County is 8%) then it's completely fair.
> And how does Facebook decide what the cost of living in your area is, anyway?
You could use the same scales the US Federal Government releases. You could base it on the average cost of living. Lots of data-points. Every state and local government collects this data for various reasons. Hell, Walmart and other large Grocery Stores most likely do this as well to localize prices properly.