If two of the three external-airspeed indicators on the Airbus models singled out by last week's directive provide unreliable readings, autopilots and automated engine settings are designed to instantly disconnect.
My understanding of what should then happen in this eventuality is that the pilots should manually maintain pitch and roll attitude and the normal power setting for the stage of flight while considering their options for continuing the flight with degraded airspeed information.
This is easier said than done for pilots taken by surprise - especially at night, turbulence or cloud, especially when they are at high altitude and heavy. In these conditions a limited safe speed range is available requiring pretty careful and accurate handling in circumstances where the pilots (necessarily) will have little recent currency and practice.
In my view following such airspeed anomalies it would be better for the 'system' not to disengage but to degrade to a basic attitude and thrust hold mode accompanied by a pretty serious warning about what was going on.