When I see the phrase, "disconnecting means," I envision a device capable of turning something off, without necessarily providing overcurrent protection. More to the point, and as an example, even if a motor and its branch circuit conductors are protected against overcurrent, we still need to put a disconnect within sight of the motor. I don't think a transformer is required to have such a thing. It must be protected against overcurrent. But the device that accomplishes that mission need not be within sight.