Here is the reply we got from Azamara:
However, I did go into the booking system and took a look at it just so I would know what we were up against.
Here is what I found. In order to take advantage of these lower prices you would have to cancel and rebook. When doing so you would end up losing your $300 in onboard credit and you would be in the 100% penalty of cruise fare. This would mean that you would lose all of your cruise fare. This would make changing your booking would not save you any money considering the difference between the 2 is only around $1400 and you wouldn’t even be able to pick your room because all that is left in your category are the guarantees which means it could be in a bad location. So, to change your booking to the lower price promotions you would have to give up $300 in onboard credit making your booking $300 more expensive since you would have to pay that $300 out of pocket to cover whatever you would like to use it on since the new promotion has no OBC (onboard credit) on it. And on that you would lose all of your cruise fare meaning you would basically just be starting over, and you would end up likely getting a worse room and be paying extra.
I hope this helps.
Cheers,
Andrea"