Simple answer, yes. But why limit yourself to poor starting point? An AoA indicator has to be the one of the most useful values displayed to any pilot. But as you point out, if the wrong datum is used, an erroneous value will be presented. And as you state, the datum will change with aircraft configuration. It is not beyond the wit of man to correct or modify the datum of the indicator as an aircraft changes configuration. Then, no matter what the aircraft's configuration (weight, or speed) a valid AofA value can be read by the pilot.