AoA sensors are sensitive to very minor deviations in the surface they are mounted to, there are aircraft which don't allow any minor damage in that area because it can cause misreadings.
You seem to have a pretty high level of knowledge of avionics. Do I remember correctly that you worked in the field? If so, do you have any idea of what the allowable range of an AoA sensor might be?
i.e., on some systems I've worked on, we had a range that a sensor was expected to be in (normal, just do regular control loop), an outer range that was unlikely (stop reporting for a while/hold control output constant to see if it gets better or worse before warning operator), and a narrower range that was flat out impossible (notify operator of sensor failure/put system into a graceful shutdown).
I assume that the engineers designing this system had something similar, but given that MCAS activated with an AoA indication of 80 degrees (IIRC) and that's essentially impossible on a 737 (or at least would correlate with a hell of a lot of other warnings), was there anything they could do to warn the operator (pilot) that there was likely a bad sensor input?
From all outward appearance it appears they failed to do any kind of range check On the data. Although people were quick to point out that AF447 had a situation where the airspeed decreased to such a low level that the warnings stopped (because it was outside of any normal flying range) which was implicated as a source of confusion.
