It's only a theory, but part of the reason I always like to put room number requests in (aside from actually wanting those rooms) is that I figure if they can't grant the request, they usually will try to put you in the next closest spot. If you request a room number, then they'll usually still work on getting you a nearby room in the same building or wing. If you just request a building or wing, then they may just resort to getting you a nearby building or nearby wing. I request room 3103 or 3145, both are in building 1 Congress Park - if I don't get my exact room request, 99% of the time I'll still get in building 1. If I just request Congress Park Building 1, they may still get me in Congress Park, but building 3 or 4...which is quite a bit farther away from the Disney Springs bridge.
At Boardwalk, if I don't get my specific room number request, I usually end up in the same wing or section...it's not the covered or private balcony I wanted, but it will still be the same 2nd floor garden view area close to Swan/Dolphin, which I like for the quiet vs pool views, and the convenience of having the Swan/Dolphin boat dock as a 'back way' to my room from the parks.
And some, like Boulder Ridge, I've strangely managed to get a specifically requested room number (a room on the 4th floor which is facing the lake and closer to elevator) 5 times out of my last 6 stays there. As in, the exact same room!