I would not expect a school that offers a preliminary package before admission, particularly from one that has a low admission rate. There are far many excessive work to do. Nevertheless, it is near the end if admission cycle that they should have finished the package for all admitted students and now focus on a small number of WL students. As the notification and decision deadline for WL admission is very short, they may need to do that ahead of time. But even in that case, they do not need to let the student know the package until admission is offered.