More People in Line Than Usually
Caterers will do just about anything you ask of them, but “toilet service” isn’t typically one of those services. However, they’re excellent at serving up swanky food and drink in the dining room.
In addition, weddings are notorious for their impatience, so having to manually refill the toilets each time will slow things down to the point where every single guest will be waiting in line for the restrooms. This is referred to as “service.”