This is the normal behavior in iOS, and has been for years.

What Apple is doing is _additionally_ disabling the USB port on an even lower level. Currently, the port could still exchange data if it were tricked or hacked, but disabling the port on a controller level will prevent accessing the device entirely.

Or at least that's the theory. Since it can obviously be reconnected after entering a passcode, there are conceivably ways to get it to open up. But that will have to be tested.