All on or all off is not a standard Airbus concept. Auto thrust normally stays in for all phases of flight.
Indeed, that is the airbus philosophy, however it is not required. In my outfit 99% of all pilots fly most if not every approach in manual thrust, whenever they do fly in manual flight. And yes, flying without flight director and/or autopilot during a normal approach is nice training and actually quite a lot of fun, as well as being not an iota less safe than automatics on to 100ft AGL for a well trained pilot.
I guess it depends a lot on how you train your pilots and the philosophy of your company.