Because they are in high demand and limited numbers, and because members arriving just days before you can reserve up to 7 nights and thus get your arrival date, the following
DVC booking categories at WDW have a real risk of being gone before you can reserve 11 months out from your date of arrival during the following times of the year (for AKV and BWV this is based on tracking the last three years; for other resorts it is based mainly on tracking allowed since June 2014 when the resort availability tool first showed up on the DVC offical member site):
AKV club level studios and 2BRs, and OKW grand villas in the Hospitality House booking category, disappear before 11 months out about 80% of the year.
AKV value studios and 2BRs can be gone during DVC's high demand season, late Sep to marathon weekend in Jan, during holidays and special weekends (such as princess half marathon weekend in Feb) during DVC's low to moderate demand season, mid-Jan to late Sep, and then just random other times during that low to moderate demand season.
BLT standard view (all room categories including 1BRs which often disapear in standard view before the studios) follows a similar pattern but not quite as bad as AKV value studios and 2BRs.
VGF studios (and as a result 2BR lock-offs) during DVC's high demand season with highest risk during the extremely high DVC demand times: first and second week of Dec, Christmas week, Tues to Fri of Thanksgiving week, Marathon weekend in Jan, Columbus Day weekend in Oct, the weekend after Columbus Day, and the weekend in first part of Nov that has the Food and Wine race. Even VGF 1BRs have a risk of missing a night or tweo during those extremely high DVC demand times. Also, the studios have some risk of disappearing before 11 months out, or more likely early in the morning exactly 11 months out, during holiday and special weekends in DVC's low to moderate demand season.
BWV standard and boardwalk view studios and 2BRs, and BWV grand villas have a risk of being gone 11 months out during those extremely high DVC demand times mentioned above. Also, particularly BWV standard studios and 2BRs, have a risk of disappearing at other times during the high DVC demand season, and holiday and special weekends during the low to moderate DVC demand season, although the risk is usually more of one of disappearing in the morning shortly after the 11 month window opens rather than before 11 months out.
BLT grand villas have disappeared before 11 months out for some nights during first week of Dec and marathon weekend in Jan.
I have also tracked DVC resorts in locations other than WDW since the availabilty tool showed up and during that time the only room category that has disappeared before 11 months out, and does so a substantial portion of the time, is the standard view grand villa at Aulani.