I was told by corporate that each resort has its own inventory control person that sits in Orlando and makes these tweaks. I would imagine it depends on the resort. But would have no idea what goes into these decisions. But Crystal Shores is particularly bad. Whole months where nothing but 7 day stays are permitted. Ironically, we own a week at Crystal Shores but don't always want to travel for the whole week - part of why we joined the Destination Club Program (now Abound). We have converted our week into points only to find nothing but 7 day stays are available at the 13 month mark, at the 12 month mark, and even at the 10 month mark.