The models are examples of what you can buy. The idea is for people to purchase their own units before they are even built. No builder wants to have "standing inventory" (built ,unsold houses) because that costs money to carry. As I recall, the original article said the houses were sold, but not closed, which is why there was that little dispute about her commissions. I think there were inventory units available, so she probably wasn't selling the model yet. IIRC,If you go to the website, it says there are units available for immediate close, which means they are complete, but not sold yet.Sounds as though these units are very close to being occupied.
Yes, anyone can go by to the models any time they are open and yes they can make an appointment anonymously, or just go there without an appointment at all. Having an appointment will not stop other people from coming by the models to look around.