Actually, it is. Way more. The reason? When the customer places the order, they agree to a price and timing for the car that is currently advertised.
SO, if they "miss out" on the changes, they are getting EXACTLY what they agreed to buy, and if they get the new changes, then they are benefiting from that.
For example, no one on this forum has paid for the new lights on Model S. They haven't been advertised yet. We are not supposed to know about those changes. Just because we know they're coming doesn't mean that any money has gone to that yet. So if you take delivery of a Model S with the old lights the day before the new ones come out, you can't complain, as you got exactly what was agreed upon.