I think the important word missing in that phrase is "any _future_ iPhone". For existing devices I imagine that a hypothetical iOSX which removes the protectio

I think the important word missing in that phrase is "any _future_ iPhone". For existing devices I imagine that a hypothetical iOSX which removes the protections would require you to enter your passcode so the OS can decrypt the data and then re-encrypt them using the new backdoored option.