They wouldn't be creating the backdoor. The door exists, they're being asked to use their key and walk through it. The exact mechanics of accomplishing that don't matter. The fact that they can do it means that the door already exists. That they publicly insinuated in marketing that this wasn't the case isn't anyone's problem but Apple's. Sounds like a lesson in not making stronger claims than you can justify.

Also, I'm not sure newer phones are unaffected, here's a line from Apple's public letter:

>Specifically, the FBI wants us to make a new version of the iPhone operating system, circumventing several important security features, and install it on an iPhone recovered during the investigation. In the wrong hands, this software — which does not exist today — would have the potential to unlock any iPhone in someone’s physical possession.

Emphasis on "any iPhone".