The reason these adjustments are being made is because the whole world isn't remote yet. The engineer in Brooklyn could more easily go get a better offer at a Wall St job then the person in Kentucky.
People who believe that we're all going to be remote and keep our Bay Area/NYC compensation levels are laughably naive. It is possible that, your compensation relative to your cost of living might improve, but long term we will see equilibrium end up closer to average remote compensation than average BA/NY compensation.
It's true employees might more easily switch jobs, but hiring remote adds a LOT of candidates to a companies hiring pool as well (which is why they're doing it). Furthermore, a push for a stronger remote technical culture with more async communications, more documentation, etc is inevitably going to make the outsourcing efforts of the 2000s a lot more viable. There's still time zones and language barriers, sure, but remote work solves several other challenges.
Finally, even if your current employer keeps your compensation the same, you have to question how it will affect your next job search.
People seem to be thinking that they are going to take Bay Area compensation and go settle in the middle of the country and live like a king. Short term that may happen, but long term it's an absolute guarantee that tech compensation stagnates or goes down because the supply of the labor pool increases so much with remote candidates. That's a major rationale for companies going remote in the first place.