We just returned from WDW, where we stayed at ASMusic. There were five of us, and I had requested the set up where you get connecting rooms with one room a king bed (for me and the wife) and the other with two doubles (the MIL and niece and nephew). I also requested the Calypso bulidings (repeatedly) because they are closest to the main building. I booked directly thru CR. I called the morning that we left for WDW and confirmed my reservations. The CM told me that they had my Calypso request in the system twice (!) so I hoped all would be well. Of course, when we arrived at check-in, we were told that we would have two non connecting rooms in the Country Fair bldgs (the farthest away), both with double beds! After some back and forth with the CM and her manager, we worked it out that we stayed in connecting rooms with double beds that night, and then while we were at the parks the next day, they moved us to the set up we wanted in the Calypso building! Everyone at the front desk was very nice and did their best to help us. The only thing that steamed me was that we could not get into our new rooms until after 4, just like a new check-in. Nobody told us, so that was frustrating. Once again, the CMs were very apologetic.
You can request anything, but they won't make any promises. We persisted, and were able to get what we wanted. We found that the CMs will try to accomodate your request as best they can. It took a day, but we were happy!