My wife and daughter are booked on UA882 (NRT-ORD, Y, 7/14) connecting to MEM, which was cancelled due to weather. I called UA to rebook. No valid Y routes on *A for the day although DL/AA routes are available in Y. I request them to be put on these routes. The agent declined my request, citing that only *A routes are permitted in weather. With many conflicting stories I heard from the premier line post 3/3, I am not sure whether this claim is true?