I find this extremely surprising. For several months, I was tracking availability for a full week rental at every resort and room type on a weekly basis at the 7 month mark. My work schedule changed and I stopped doing it, but in tracking weeks from mid-June through September, you could always get multiple room types for an entire week at ANY resort at the 7 month mark. Admittedly, this was within a day or so of the 7 month mark, so maybe you have to act relatively fast, but I was purposely NOT checking at the stroke of 8 am, giving a little time for a mad dash to subside.
I recognize that these are perhaps among the least difficult times to get reservations, but that is really my larger point: whether you need the 11-month window is ENTIRELY dependent on where you want to stay, what time of year, and what room type (as well as how long, but I'm assuming a full week). For example, in the 15 week period I checked, if you needed a 2 BR villa for a week, you could have reserved that at ANY WDW resort for ANY of those weeks, with one exception: 3 out of the 15 weeks at Beach Club (for 2 of those weeks, 6 nights were available).
On the other hand, there were certain specific room types/views that were never or very rarely available for a full week at 7 months out (e.g., 2BR club or value at Jambo, BLT standard for any room type).
So the bottom line is that it really depends on when you go, where you go, and what type of room. It is certainly not generally the case that you can't get a room anywhere but SSR 7 months out, but in a shorter timeframe, or at a particularly busy week, or a very popular room type, that could be the case. For my situation, we are relatively flexible in our travel schedule and don't have a preference for one resort (in fact we want to try many if not all WDW resorts). Buying the best value was what made sense for us, and at the time, we deemed that to be SSR resale.