The only time I've noticed any problems with availability at the 7-month mark was for the period around mid-June. In 2012, Aulani changed from the Choice Season to the more expensive Magic season on June 27. I think a lot of people were trying to save points by booking right before the season switched, resulting in some accommodations being unavailable in mid June. My sister booked a 1-bedroom for 6/15-21/2012 right at 7 months, and she was told by the CM at MS that she was getting the last 1-bedroom for those 6 nights.
Good luck!