Not automatically! You or your travel agent will need to call and see if the new discount can be applied to your existing reservation. Sometimes you need to change resorts to find availability, as they only make a certain number of rooms available for each discount at each resort.if i make reservations for a trip and then a discount becomes available, like a room discount or free dining, will i be refunded the new discount?
If you book a room directly through Disney, they will refund the difference on your balance due.
Check this thread http://forums.wdwmagic.com/showthread.php?t=353270
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