Off the top of my head, if you do any poolside service, they bring you your check in one of those black folders like you get at restaurants, and you give them your room key or credit card to scan in the back. I imagine you wouldn't want to hand them your phone or watch.
They've been slow-playing the MagicBand rollout. They're still not for sale in their stores and it's not advertised anywhere, so it's just the people who have been to Walt Disney World and read message boards who have any idea that they work. I think you're right long-term, but I don't know how fast they'll get there.With MagicBands now active, I'm thinking a wireless terminal would need to be brought over to process payment when using one to pay. That same terminal may be able to process Apple Pay.