I booked a AAA room and 4 park hoppers about 1 1/2 weeks ago. Yesterday I changed to the Visa package with the free WP&M upgrade. The CM cancelled the old reservation and made a new one. I had a preferred room at ASMo and I got the same thing with the package. Might be harder to get the same room at a better resort. Surprisingly, the package was cheaper. I didn't ask if he could just add the code to my old reservation, so I can't say for sure that you can't do that, but the CM didn't offer to do it that way. When the Visa offer you want is announced, you should just call them and try it.