I'm afraid I disagree. For 'a long time', stick pushers worked on IAS alone, and for an AoA driven pusher to 'malfunction' would require it to 'achieve' a critical AoA in the first place - in which case its 'shout' was probably valid!
The problems are occurring because AoA is now so deeply embedded in the control system that a malfunction has a far more serious effect then ever before. If I recall PGF correctly, a 'sensible'/working AoA was 'voted out' through the logic circuits. The 447 AoA problem was caused - only once a stupid AoA had been achieved - and the IAS logic removed the stall warning. Not really a 'problem' with the AoA sensor itself which I understand worked correctly - again, a problem with its interface with the system. Agreed they should not 'freeze' but equally their effects when so frozen should be easily negated. While AoA represents an excellent performance guide, you do NOT need AoA to fly an aircraft safely under normal circumstances.