I was told by my guide that once all the paper work is done, you will be able to book your "free" stays. The black out dates have been posted, and no one has hinted they are incorrect. My guide also said that there is no "artificial" limit on these stays.
You can book any resort listed on a "first come, first served" policy, which is only limited by the actual number of standard view/type rooms available. There is no artificial limit like some of the discount rates (AP, DC, or code). The free stays may be booked as little as one week in advance or up to 7 months in advance. Rooms may not be upgraded at time of booking, or at check in.
I'm going to take the free nights!