Unfortunately the membership benefits are not guaranteed. It's absolutely in Disney powers to decide that to get discounts one has to have a smartphone.Disney doesn't have to make a physical plastic card, but they have to make some way to print out a QR code or something. Or there will be lawsuits.
It's funny that they went from really don't care at all to rush a massive IT fail. Anyone with a minimal Photoshop proficiency could have created a digital card in 5 minutes, and they've accepted those for years. Well, one could still create a fake phone app that looks like the digital wallet but shows a fake DVC Y. Until they start scanning a QR code with a signature that expires every few minutes, they're not really enforcing anything.
I'm so glad I won't visit the parks for a while, I'll add this digital card to the long list of thing that I'll wait to be resolved before I'll be back.