I think delivery week is dealer delivery, not customer delivery. That would be consistent with the dates we were all originally given. All of us had build and dealer delivery dates 3 weeks apart to start with
It also wouldn't make sense for BMW to talk of a customer delivery date when they have no need of knowledge of the customer. Lots and lots of cars are built for stock and built for demonstrators for dealers, built for pre-reg, built for ... well built for anything other than a customer. BMW (Ze Germans) only care about getting an order to the place it was ordered. The rest is out of their control