>"As a director of a team at a mid-sized tech company who had conversations with employees making decisions like this, I can tell you that it is standard practice to adjust salary for the cost of living and the availability of talent in a particular market."

It's standard practice for your company maybe. This hasn't been my experience at all. I have had three jobs where this was not the case. I've had colleagues who have experienced similar as well. People should be paid for their time. I can't even believe a company would want to engage in salary reduction negotiations with employees they value.