Once a real problem is evident with booking at 7 mos. out, I do feel Disney will restructure something, thus leaving those paying higher dues with falling resale values something to think about.
I'll just point out that the whole question of "if" or "when" there will be a "problem" booking 7 months out is not exactly a new debate. It's been going on since I joined this forum over 5 years ago and truly dates back to when the second resort was introduced (those BWV rooms are so much smaller and cost more points--I'll NEVER get into OKW again!)
The only ones who have access to their Home resort at 11-8 months are the owners of a resort. And whether it's 2007 or 2037, the number of points at a resort cannot change (without additional construction, that is.)
The fact is that owners at BWV (or BCV or VWL, etc.) do NOT consistently book their home resort prior to 7 months. That means that there will OFTEN be rooms available at 7 months. It doesn't matter whether there are 100,000 or 500,000 DVC members. If the small subset of BWV owners doesn't fill their Home, there will be room for others.
What gets trickier is looking at the number of people trying to book the available rooms at 7 months. Obviously there is a lot more competition if you have 500K members competing rather than 100K members. The best way for DVC to control this is to build resorts with unique appeal. Right now BCV is probably the most in-demand resort. But will that still be the case when AKV is open? How about if the Contemporary is next?
Disneyland? Hawaii?
People (still) like to beat-up on SSR as being sub-standard compared to the others. But the reality is it does have its own niche. It has the best spa and workout facilities in the program. It is the only DVC resort with an on-site golf course. It is the closest resort to Downtown Disney. While those features don't appeal to
everyone, there clearly is a market for them. Perhaps one could argue that SSR is oversized now in comparison to other program inventory. But once DVC adds hundreds of room at AKV, the Contemporary, Disneyland and a handful of other sites, that disparity will quickly evaporate.
With every new resort that Disney adds to the program, demand will shift and change. Disney does retain the right to shorten the Home resort booking window, but I think it's far from a certainty that it will ever happen.