Yes, they will send you an email letting you know it has been sent. We had a split stay at Poly and the YC. We did not get the room or longhouse we requested at the Poly. We requested balcony, Fiji, facing the Grand. Instead we were placed in Aotearoa facing the monorail. We did get the third floor balcony we requested and the longhouses are adjacent so I guess you could say we got the general location. We did ask if any of the Fiji rooms we requested were available at check in, and she said only a second floor in Fiji which we did not want.
Aotearoa ended up being a lovely location, close to GCH, the pool, and the beach. We loved watching the monorail go by (could not hear it at all from our room), and we were happy there. I loved sitting on the balcony each morning, so glad we had that.
At Yacht Club, we did get the room next door to the one we requested (and we booked a standard view but requested a room that was considered Garden View). I wouldn't necessarily recommend doing that, but we did it to give a general location, not knowing what rooms were considered standard in that area.
Would I send the fax again? Probably. My greatest request at Poly was a third floor balcony, so that request was granted.