Technically, your resevation isn't cancelled because if it were, you would have a new reservation number, but the new system does make you pay the current ticket price of the date the promo code is added. Not only did it throw us off, but the CMs were thrown off, too. Many of them questioned it and had to get the new info from their supervisors Monday morning when the Visa offer went live.
Unfortunately for us, it did. Our TA called Disney at 5:30 am and was on hold for 3 hours. When a CM came on, she was told that only the pirate themed rooms qualified for FD. My family already had that. However, my mom and brother did not as they opted for a non-themed standard room with water view. Our TA had to upgrade my mom and brother's room to pirate themed water view so that they could get FD. She also upgraded our room from a standard pirate room to a water view room and requested adjoining rooms for us. Because of the changes to our room, we were paying $400 more and my mom and brother were saving $600
(I'm not about to try and figure that one out).
My mom wasn't thrilled with the changes even though it was saving her $600 (both of them specified that they did not want pirate themed). I also told her to look at it this way, we are not in the rooms that much and will be at the parks all day plus it's saving her and my brother $600. The other way would mean that she would go back to the original room she had and pay for the DP. In the long run, paying more.
About an hour or so later, our TA called me and told me that she went online to the TA's web page and lo and behold a standard non-themed pirate room opened up for FD. She instantly grabbed it and put us back to what we had. So after all of that, changes to our existing ressies so that we can all get FD and then back to what we originally had, we saw a slight increase (about $60 for us, don't know about my mom and brother) in our final balance. And of course, we now have new reservation numbers b/c of all the changes, lol.
However, I can't really complain. For one, it's less than a $100 increase and I'm ok with that. Two, our TA went above and beyond for us by calling Disney at 5:30 am on her own time (her office opens up at 10 am) and staying on hold for 3 hours just to make sure we got FD. To me, that shows that this agency cares very much for their customers.