FWIW I agree that there is nothing wrong with moving over as a courtesy. But some caution should be exercised as some drivers see this as a signal “it is now safe to pass” so avoid doing this on blind turns and such. Another caution is if three or more cars are queued up, the latter cars may not be aware of your presence and possible not pass you safely.

Drivers’ behavior can vary drastically from one local to the next so YMMV.