Refresh cache notes is specificially not the corrected coordinates. It is what it says it is:
"Refresh information about your personal cache notes."
The point is that the API does not support fetching a list of caches for a user of which caches he or she has corrected coordinates for. It does, however, support fetching a list of caches there are personal cache notes on.
The consequence of this is that project-gc has no way of knowing which caches to ask for a corrected coordinate on. This would be a doable task if it was "just" for the caches that the user had found (or otherwise posted a log entry on) but usually that is useless - most logs are "found it" and a corrected coordinate is seldomly useful after the user has found and logged it.
The consequence of this is that project-gc needs to be told which caches to refresh coordnates on for which user and when to do it. The "Refresh GC code" might do that (it is a request to refresh an individual cache), but the "Refresh cache notes" most certainly will not do that.
EDIT:
Documentation about corrected coordinates vs. personal cache notes:
https://project-gc.com/Home/FAQ#3173226005