Even without the blackout, what may be going on is that the hotel has put capacity controls in place for those dates. The days of "if you can book a standard room for cash you can book it for points" are gone. So long as the hotel makes one standard room available for points (no matter how many standard rooms are available for cash) then the hotel has met its obligation in the eyes of Marriott. Doubt you'll have much luck changing this. In my opinion one of the biggest "enhancements" from the merger