I guess just to be in the system for deliveries. Nobody knows for a fact that there’s a “line” for orders to be fulfilled. Grant approval is also a case-by-case basis — sometimes it comes fast, sometimes it takes a really long time. In some cases, approval does come before delivery happens. For me, it was taking my chance on minimizing the wait.
Battery Day is non-issue for me. There’s nothing wrong with waiting, but I’m a believer in there being no immediate changes to the Model Y regardless of what is announced on Battery Day.