First, a guest may really like one of your occupied rooms and adjust their vacation in order to stay in that room. Second, it is never a good idea to appear less than you are. By hiding the unavailable rooms, a 20 roomer can feel like a 2 roomer. Webervations implemented hiding occupied rooms is one of the biggest complaints we get from innkeepers coming over from Webervations to ResNexus. This could cause a potential guest to either move on to one of their competitors or comment as they call that they didn't know the inn had so many rooms.
Please call your Red Carpet Professional if you have any additional questions.