I wish posters would try to be more specific when asking questions such as these. Would you ask and expect to get a useful answer if you asked "I am trying to book a room in the US in September?"
Europe is a big place ,,, believe or not

That said there is no evidence and I dont believe its the case that more award rooms are released closer to the dates required as may be the case with airlines. September is often the highest demand period in some cities/countries ( for example Paris with the Auto show and Fashion week) and unless one is Diamond and can make a Special Request you may have some difficulty.

mike