Well... yes?

If digital widget producers are worth $x to the company, and get paid 0.8x in one location and 0.4x in another location, I'm not sure why I'd regard that as anything other than exploitative.

CoL isn't really related to the market value of labour for remote-capable jobs; it would be similarly exploitative if the company paid childfree people, vegetarians, and basement apartment dwellers less because of their drastically reduced cost of living.

I could see a point for fairness if the salaries were scaled so that average post-CoL savings in different CoL areas were equal, particular within regions (e.g. a country) where people have freedom of movement.