What you are seeing from early Dec is not itself a matter of significant concern. Early Dec just happens to be the highest
DVC demand time of the year at WDW and thus anything at a near park resort has some risk of disappearing quickly once the 11 month window opens. The reality is that VGF dedicated 2BRs and GVs are actually open much of the year even at 7 months out. And if it is a 2BR at VGF that you will usually want then you can safely purchase there; in fact if your desired times did not include first two weeks of Dec, I would suggest you seriously consider buying resale elsewhere such as SSR for about half of Disney's price per point becuase those dedicated 2BRs at VGF are likely to be open much of the year at 7 months out.
But since you mentioned you are looking at both VGF and Poly, I am assuming your have an interest in studios (unless you can actually afford the astronomical points needed for a bungalow at Poly). In that case, you have a reason to be worried and that includes both VGF and PVB. What has happened in the last four years with new resorts is that Disney has managed to raise the combined price per point and points needed per night by about 60% over what most of BLT, a resort itself that was considered quite expensive, actually sold for. VGF has 47 dedicated 2BRs (meaning they can only be 2BRs), six GVs, and 47 lock-off 2BRs. It is the lock-offs that actually get reserved as studios and 1BRs. What has happened with VGF is that it is so expensive that the vast majority of purchasers from the target audience could afford to buy only enough points for studios. However, Disney got to sell to those purchasers all the points also applicable to larger rooms.
The same thing is likely going to happen at PVB with its 360 studios. Most purchasers will want to reserve studios, for which points per night will be about the same as VGF studios, and not the 20 bungalows, for which points per night will actually exceed the VGF GVs. Moreover, those PVB purchasers who can actually afford more than a studio and want a larger room will opt to buying enough points for two connecting studios rather than for a bungalow, assuring more stress on the reservations for studios. Tough few can afford to buy enough points to use those bugallows, all of those bungalow ponts along with studio points will be sold to purchasers wanting studios and connecting studios.
Net result: Disney has created a situation where the demand for studios at a new resort greatly exceeds supply. Studios at all resorts are the ones in highest demand but at older resorts it is nothing like the schism that exists at VGF between studios and other room sizes and will likley exist between studios and bungalows at PVB. That problem is now coming to fruition at VGF. As it gets closer to sell out, members are discovering for high demand times in Oct, Nov, and Dec, they can even be blocked out of studios at 11 months out because other members with vacation start dates just before theirs can reserve nights including their start date before they can reserve it.
DVC at WDW currently has two demand seasons, low to moderate demand season from just after marathon weekend in Jan to near the end of Sep, and a high to extremely high demand season from the end of Sep to marathon weekend in Jan. Though holiday times are more in demand than most other times during that mid Jan to late Sep period, it is far easier to get rooms at Easter time and July 4 time, including at 7 months out, than it is for any time in that last quarter of the year. In fasct the highest demand time during that mid-Jan to late Sep period is the Princess half marathon weekedn in the latter part of Feb.
If your usual and only time to vacation at Disney will be between mid-Jan and late Sep, then you are likely going to be safe with the 11 month window for a studio at either VGF or PVB and will have opportunities for other near park resorts at 7 months out. However, if you are intending to go during DVC's high demand quarter, you could face a risk at times of even being blocked out at 11 months. DVC's extremely high demand times during that quarter are the first two weeks of Dec, Christmas week, the Tues through Fri of Thansgiving week, the Thursday to Monday of Columbus Day weekend, the Thurs to Sun of the weekend after that, and the weekend that either includes Veterans Day or comes just before it. It is those times where there will likely be a risk of being blocked out from studios at VGF and potentially PVB even at 11 months out. There may be a risk even at other times during that quarter but those are the more likely candidates for a problem. Though one might think the problem may not arise at PVB because of the sheer number of studios, the number of points applicable to those bungalows is huge and will be sold on top of all those poionts applicable to studios and unlike VGF, anyone who desires and can afford a larger room at PVB will be getting connecting studios rather than a 1BR or 2BR, which do not exist there.