Logistics and scheduling have exceptions. It can happen that a scheduled delivery is bumped for all sorts of reasons. That does not mean that your change caused the bump. There is a remote chance that they have a Just-In-Time allocation for supplies and their stock is so limited that any minor change will bump a delivery, but in that case the reliability of the shop floor is in question and I cannot imagine BMW would do such a thing for what is essentially a cash cow for them (considering how well sales are going).
I had to wait for nearly a month before my car was shipped from Toronto to Regina, not because it had not been produced or shipped to Canada, but because there was a shortage of rail cars due west. Sometimes these factors just pile up and we notice.
It all goes away when you take delivery