I used to fly early A320 (s/n in mid-200s) with analogue electro-mechanical AoA indicators set outboard of PFDs but the only thing they provided was some poor inflight entertainment.
AoA indicators provide almost no usable info at cruise airspeeds. The AoA/airspeed curve shows a very small AoA change for a given change of airspeed at cruise. On the other hand, AoA at approach speeds provides a very precise indication of where you are on the lift curve.
BTW, my comment on AoA earlier was just an aside. My real point was the crew in this accident weren't watching their airspeed. However, AoA is the premier way to avoid a stall. Stall recovery using an AoA readout gives you the simplest means of getting to L/D max.