I think you may be misunderstanding how perks work with
DVC.
They're not part of your membership. That's important - the ONLY thing that the contract guarantees, and what you're really buying, is the right to stay at your home resort, subject to availability. Everything else is subject to change.
Most perks are given at the whim of various third party entities, and come and go frequently. Most, with the exception of the current AP discount, are minimal - 10% off this restaurant, etc. Sometimes there are a lot of discounts, sometimes they're pretty sparse.
For instance, the AP discount. Disney Parks gives us that discount because their numbers apparently show that DVC members come to the parks more frequently (and spend more money in shops and restaurants) when we get APs. If those numbers change, the AP discount goes away. Probably with no warning. That's the way the perk changes happen. They're there, and the next day they're not.
DVC is a timeshare, not a discount club. It's all about the lodging. Nothing else is guaranteed.