In fact, even on the day you check in, if the room is not ready, the front desk will not tell you the room number. I assume that's so the nobody will bother the previous occupants (if they haven't checked out yet) or the housekeeper.
At OKW, you can get your resort ID key cards any time on the day of your check-in, even if the room isn't ready. They give you a number to call to see if your room is ready; if it's ready, they tell you the room number. You can then go directly to the room without returning to the front desk. I assume it's similar at Boardwalk. Can somebody confirm this?