The part of the contract that is obviously unenforceable is the idea that signing up for a Disney+ trial a year ago forces you into binding arbitration over an issue at a Disney theme park today.

That's very easily enforceable. It's bad. But there's no difficulty actually imposing the rule.

Disney really shot themselves in the foot by even trying to claim this.

They have oodles of money and a highly favorable court composition to argue in. Forcing anyone who has every touched a Disney property into binding arbitration would be an enormous coup for their legal team. Meanwhile, they aren't going to lose any money on this gambit.