tobrown and ToTLaugher,
I just called CRO to inquire after reading your post. They told me that as long as I had the voucher in hand, they would honor the discount. We have done it this way 4 or 5 times now. However, if they insist, then you just have to go to the park and activate them before checking in. Easy to do and you don't have to enter the park, even. You could try to check in and if they ask for the activated pass, tell them you will be back to check in later, then go activate them.
Official policy, however, is they should be activated, but they have never given us a problem.
I called my mom, who has been going and getting AP's and discounts for years before us, and she stated the same thing.
Still, if it eases your mind, it is very easy to activate them.
When in Dec?? We will be there 12/26-1/1.