I feel like if you're a remote employee they don't need to have a right to know where you are living, they only need to know your timezone for planning purposes. Your location should be abstracted out of the equation by remote work tools.
As far as they are concerned you are just an amorphous existence on the planet that is online to provide skills from some time UTC to some other time UTC and they shouldn't have a right to know anything more than that.
However, it may be beneficial for Facebook to do it that way, as they can then get decent talent around the world at a lower price.
Once Bay Area tech engineer moves to some far off corner of the world, there won't be much differentiation except for raw talent, and there's plenty of raw talent out there in the world who were born in the wrong place.
They do pay this. It costs a heck of a lot more to hire in The Bay Area than it does outside, and much of this increased salary goes to landlords and rents.