I suppose, conversely, under the heading of "perks aren't guaranteed", they could come back with some sort of marketing pitch that reads "Disney may, at any time and at its sole discretion, introduce additional perks, including complimentary Annual Passports and unlimited Fast Passes", exclusive to Disney's Vacation Club memberships purchased directly from Disney Vacation Development. Or something to that effect. They have the right to give and take as they please (no contractual obligation), and they aren't actually promising it. They're simply mentioning it as an "example" of what they "COULD" offer. And, if you were an original Disney's Vacation Club owner, it was a perk that you did in fact enjoy, so it's at least arguably within the realm of possibility.
Couple that with a guide saying something like "Well, it's not available now, and I can't say if or when it might happen, but.............. I have heard talk, and they did specifically add that to the memo that went out, so..........