Obviously, they have to objectively pick a date and stick with it… What a mess it would be if they start sliding the date to accommodate a customer (opening a whole new group who missed the new date by one or two days). Or even messier if they start granting exceptions to individuals who are outside of the date.
As you always register the USB-eLicenser containing licenses, it will be a Cubase Pro 10. Activating a Cubase Pro 9.5 license (full or update) now, will always provide a Cubase Pro 10 license instead.