FYI at least for US bookings
Your TA has access to boarding passes and cruise docs as soon as you book a cruise. I have mine and my cruise isn't until May of next year. It lists all of my OBC. Obviously for any bookings out a ways it will change, but for all of you concerned about not having anything, talk to your TA! I am told they can find this under the consumer documents tab, same place they would print or email a confirmation from.