I've watched this scenario play out several times now, and in our own practice it's not uncommon in the October/November period after we take on a new surgeon to have openings. An increase in doctor days (as much as 20% with a new surgeon) and native growth in the practice of 8-10% means space in the day.
The natural tendancy is to try and fill the day. If the day is filled by increasing sevice levels to patients that's great. However, the common approach is to add time to existing appointments.
When a practice accepts a new provider create the following checklist:
1. List appointment types and expected length
2. Use booking templates
3. Review the templates with booking staff then make sure they're followed
4. Allow for more 'urgent' visits. Rather than having a policy of booking days or weeks ahead ask patients if they'd like to come in that afternoon.
The danger of open appointment slots is adding inefficiencies to the schedule by the pressure to fill time. Instead, look at native growth, the change in provider time and have realistic expectations for open time in the first year.