The maximum occupancy for the VGF GF is 12 - I assume one of your party is under age 3 & doesn’t count for occupancy purposes which is how you planned to fit 13 into the GV?
A couple of facts to keep in mind as you negotiate w/ a supervisor:
VGF GFs cost a lot of points - not even a 1 & 2 bedroom lake view villa combo costs as many points as a GV - make sure whatever replacement combo they offer you costs an equivalent number, & if not insist they return points to you & if you borrowed points insist they put them back into their original use year & that they waive holding & banking deadlines so that you can bank any current use year points. My personal goal here would be to salvage enough points to reschedule a GV sooner rather than later.
The VGF GF is 2800 sq. feet, I’d ask that whatever solution they offered total 2800 sq. feet, a 2 br. is 1232 sq. ft., so not even 2 2 br. villas gets you 2800 sq. ft.. Moreover, I suspect they won’t have 2 2 br. villas available to offer you, perhaps the ‘resort’ can find you a couple of suites w/ club access to make up for the loss of a kitchen & dinning table that seats 10?
I doubt that it’s a mechanical/room issue, since they are waiting 2 weeks before they fix it. There have been booking issues at other resorts, most famously the Grand Californian - twice, and overbooking due to refurb issues, most recently w/ the BWVs. Perhaps since you booked ‘almost 11 months ago’ the other 5 GVs were booked exactly 11 months ago? In any event I’d probably mention that the POS requires that DVC be operated on a first come first served basis & ask for confirmation in writing that this contractual obligation was followed in this case.
Frankly, the response that ‘the resort decided’ isn’t good enough IMO. Although WDW (‘the resort’) plays fast and loose w/ cash reservations a lot, overbooking popular rooms & then offering ‘upgrades,’ DVC as a timeshare is bound by it’s contractual obligations to you & Florida’s statutes regulating timeshares, thus, irrespective of what I was offered as a replacement I’d file a complaint w/ the appropriate regulatory authorities as well
https://www2.myfloridalicense.com/lsc/timeshare/documents/TimeshareComplaintForm-English.pdf