Be careful - In Feb, I received the same offer. I was told by next cruise to cancel the original booking and rebook new offer. When I received the invoice, they applied the dollars off instead of the free cabin as there were no casino cabins open, and I had a $5000 balance. Fortunately, I found out while I was on the cruise and asked them to give me my original booking back - took days and finally the casino host was able to rebook cruise with original offer. Lesson learned to never cancel a booking.