I'm not sure if this is true for DL, but at WDW when they offer deals like this AP holders can book the package as long as they purchase at least a one-day park ticket with it. Then, as long as the park ticket is not used, they can apply the cost of that ticket to a future ticket purchase (so when they go to purchase their next year's AP they just pay the difference).
DL may be different, though! Maybe someone else can confirm?