CP parent here...When we checked DD in last month, there was a DVC rep at the parent area talking to all of us who were waiting for our kids. Here is what we were told:
If you, or an immediate family member, purchase DVC while you are a CM in the program, there is a 15% discount on the price of the points. Once your program is over, the discount is gone.
I called our DVC guide after I got home to confirm since we are already DVC members. According to my guide, the discount only applies to resorts that are currently offered to the public...SSR, Aulani and BLT. All other resorts are considered "SOLD OUT" and are only available as add ons if DVC has returned points in inventory so the discount does not apply.
I don't know if you get the currently offered incentives on top of the discount. I didn't think to ask that.