The critical jump pilots had to make was that this was a trim runaway event. AOA indicators were not connected to the trim system before.
Unless you change it to "It’s certain the AOA disagree light would not have saved the two flights", you are basically arguing for presence of AOA disagree light.
In this case I agree with the FAA's initial decision for this indicator. Its extremely unlikely having it working would have prevented the two crashes. The mere fact that it might have helped doesn't make the original decision incorrect.