If you are considering walking for BWV standard or boardwalk view studios/2BRs or BLT standard view for early December, the safest course would likely be to begin 11 months out from the Thurs before Thanksgiving. Both resorts are highly likely to be open then. Starting during or even after Thanksgiving week leaves a risk that dates you are trying to start walking with will be gone before or immediately after the 11 month window opens.
As to necessity for walking, this appears to be a changing landscape. Three years ago, you could have gotten anything 11 months out any time of year except for AKV club level and the OKW GV in the near Hospitality House booking category, which are unsolvable problems usually gone 11 months out many times of the year, and except for some risk for AKV value, BWV stand, BLT standard and BCV studios (and resulting 2BR lockoffs) during first week of Dec and time around NYE and even that risk was non-existent if you reserved starting with the Sunday after Thanksgiving for early Dec and reserved starting before Dec 27 for NYE. It started getting worse in 2014 and then even worse again in 2015, spreading to other times in that last quarter, and VGF was added to the mix with its studio problem created by the extreme oversell of the studios (Disney legally sold most of the points for larger rooms to members who were buying enough points just to get studios). In 2015, early December and Christmas week became more of a problem and times around Thanksgiving, Columbus Day weekend, the weekend after Columbus Day, the Food and Wine race weekend in Nov, and marathon weekend in Jan also saw some issues. Moreover, VGF 1BRs also developed a problem for first week of Dec (when no one can get studios, the 1BR is their only possible alternative).
With 2016, I have thus far seen a small number of days, usually close to holidays, having the issue between mid-Jan and mid-Sep for AKV value, BLT stand and VGF studios (again with resulting effect on 2BR lock-offs). For Oct 2016, BWV standard and AKV value were gone the majority of days the first half of October either immediately after the 11 month window opened (where you are playing the game of whose computer is faster in communicating with Disney's at 8 a.m.) or in some cases before. VGF studios had the same issues during Columbus day weekend. BWV boardwalk view and BLT studios had a couple days with issues and it was surprisingly the BLT standard 1BR that developed issues over Columbus Day weekend of being gone before 11 months out. BWV grand villas did not have the issue except that on Nov 15, they all filled for Oct 15 to 20. Beginning the Monday, a week after Columbus Day, it was generally better all around with most things being open for at least enough time to reserve even if your computer lost the race once the 11 month window opened, except for BWV stand studios a few times. I suspect we will also see more 11 month issues this year as we go through the rest of 2016.
As to walking, it is difficult to detemine how much of it occurred for Oct but there were days popping up after closing out at or before 11 months out except that occurred little for BWV standard or AKV value, while it most often occurred for VGF studios. Moreover, BCV, VWL, Poly, BWV pool/garden, BLT lake and theme park view, and Grand Villas other than BWV GVs and the Hospitality House OKW GVs, are still open for all of Oct, so if anyone was walking any of those, it was definitely a waste of energy. Moreover with BWV stand and AKV value, unless you started walking in late Sep, you would have faced issues finding that day that was open to start walking if you wanted first half of Oct.