For those of you who request rooms here is some info on how the rooms are assigned. This is an example at the Polynesian resort but most of this applies to all the resorts.
Lets start with saying that requesting a room, building or anything else is best done when you make your reservation. If you try and get the request in later there are factors that could lead to it not being noted properly. Also when you call the Polynesian phone number and speak to someone, that someone is not at the Polynesian at all. They are in a call center away from the resort and in most cases have little knowledge of the resort. Emailing any request can only be done if you are staying concierge since there is no email address for the Polynesian other than the email for the Planning Office. Faxing request was not only discouraged by CMs at the resort but can end up being thrown out with the other junk faxes that come through. It does sometimes work but a while back official memos asked that faxed requests not be taken.
So as far as when the resort gets your reservation and request, here is what someone at the resort sent to me as an explanation not too long ago.
“The room reservation comes from the DRC (disney reservation center) to the resort 5 days out. (we cant see the resv. in the computer till then) Then the rooms team go thru all the requests and try to meet those based upon whats currently checked-in.Reservations without a request dont get assigned and at Check-In the computer does whats called a "auto-In House" (the computer looks at the rack and sees whats available) (holes) where rooms are empty and comes up with a list that the Cast Member can select from before the keys get cut.If your a group/ Magical Gathering they (the rooms team) will really try and book the rooms together "pre-assign (the reservation has room #'s attached)" and find open rooms for this first. Again if the rooms have no requests then the computer grabs the room, suggests to the CM whats available, the CM can select one of the 5 rooms that "pop up" or go into the rack and find a "working vacancy" and then check with the Rooms Team if the new room works for a fit for the (holes) that are in the system. Downside is when we are 100% occupancy the computer will start issuing smoking optional rooms as whats left.”