In 15 years, SSR will only have 18 years left on it. While 18 years is still a long time, it's likely that it's value will start to drop because people will be making the same arguments about SSR that they do about the 2042 resorts today. Of course with inflation and rising costs, this probably means on a pure dollar value, you may get what you pay today, just it'll be $100-$120 in 2036's dollars.
BLT will have 24 years remaining; PVB 30; and CCV 32. They'll all probably hold value well, though you will likely get people starting to look sideways at BLT in terms of length of contract vs length of contract of PVB & CCV. That said, it's location will always give it a edge, just like BWV & BCV.
While PVB's
point chart is not as favorable as BLT and CCV, and it doesn't offer 1BR or 2BRs, I think it will likely retain its value because it has a lot of nostalgia value and is well-loved, and it's location between MK and EPCOT on the monorail is great. It has very large studios, and is the only
DVC resort to offer *connecting* studios.
CCV has a great point chart compared to BLT and PVB, and is also in a good location. I think as the 2042 resorts disappear, it's point chart will position it to be of higher value long-term (and it has a 2068 expiration). Studios are an issue, but a family wanting a low point studio in a great location will therefore be driven to purchase at CCV, since you won't be able to get studios reliably at 7 months unless you own there.
I think any of PVB, BLT, or CCV will hold value, and I'd be cautious about SSR. If it were me, I'd likely buy CCV first, PVB next.