It surely delay process & depend on office too. It’s been more than 6 wks after interview. No update. USCIS said delay in oath is due to name change
here is the response
The oath ceremony is not a regular one, it's judicial, because there was a request for a name change. Unfortunately these types of ceremonies are not held as often but there is a request pending and the liaison has said they will flag another time to make sure you are on the soonest scheduling possible. I'll continue to monitor and update you should we receive new information.