Hi Joseph, you can actually already do this.
If you go to Schedule configuration, you can find the calendar you want to rename and just enter a new name. We continue to use the provider's AC username as the key when communicating with AC, but you'll see the new name in Updox and in the patient portal. (there is a small paragraph there explaining this)
Technical discussion: AC does not have the concept of calendars, only providers. When we sync appointments over from AC, we create a calendar for each provider that has appointments. We default the name of that calendar to the provider's AC username, but as I stated above, you can change that name. We will still use the username to sync with AC but you (and your patients) don't have to look at it everyday.
Hope that helps.