By defintion, all
DVC "perks" are temporary and not a fixed component of ownership. Thus, they may be changed at any time. This includes the current list of dining discounts, pool hopping, discounts on recreation, etc.
Over the years we have seen many changes in the member benefits (perks), but I just prefer to think of them as an evolving component of membership. Even the ability for non-home resort reservations at 7 months and the specific number of points needed for a given room on a given night can change (the only time the
point charts have changed was in 1996- so it can and has changed).
The free admission passes were not really a perk, they were the first sales incentive and the December 31, 1999 end date was written into the contract of all who got them. There was never any confusion about that program going away.
We have had changes in the golf program, the dining program has gone away and the dining discounts change frequently. The 10% discount on UPH passes has also been discontinued (since the UPH pass itself was discontinued), but has been replaced with the current discount on AP/PAP. Most were delighted with that offering and a few have voiced disappointment over that change. The offerings in the World Passport and Concierge Collection have changed - losing some options and adding others (I think more have been added than lost).
Perhaps we should focus on the guaranteed, unchangeable aspects of ownership. We are contractually entitled to the 11 month reseravtion priority at our home resort and the total number of points at that resort cannot be changed (thus any increase in points for a given night must be balanced by a corresponding decrease for some other nights). Beyond that, most aspects of DVC ownership can (and probably will) change over time.
I'm going to enjoy what we are guaranteed and not worry too much about what else is offered thru our membership. Everything else is the icing!