The NTSB has always shown a mixture of ignorance and unwillingness when it came to this rudder issue.

The pilot control system (= pedals) on the A300-600 is below optimum. There is no doubt about it. It can relatively easily lead to pilot induced oscillation.

The A320 works different.

What those guy did was at first crappy piloting. There is no need to use rudder in flight as the aircraft is “self-stabilizing” with its yaw damper.
And even if there is a need to use the rudder, decide on one direction and keep it one direction (vertical tails are designed to withstand full pedal application at all speeds and altitudes).

The problem is an oscillatory movement. You can achieve higher loads than when you just use full one sided rudder application.

At first pilots need to be told that large aircraft are not built to take any control action at any speed in any combination. Usually a pilot can fully use one control (rudder, aileron or elevator) at one time to full extent. A combination is not covered by certification requirements.
Further, oscillatory movements are not covered by certification requirements.

There are over 4000 Airbus Single Aisles in service, which have flown 5 billion people. If something happens with an aircraft that has seen 20 years of successful service (with some flaws sorted out in the mean time), I would first ask if the crew performed well.

In consequence, pilots will have less authority in future aircraft.
Say welcome to A380 and A350 rudder control system.