Flagon
Details would require you clarifying deeper the exact issues, but in principle I would say:
a) This is a double failure, and (from your post) determined as such by the systems. Therefore Flt Ctrl laws will usually degrade e.g. to Altn Law, protections reduce i.e. you will be able to sort it out if you correctly assess the situation
b) If 2 ADRs determine they have a valid, and similar AoA, they will be believed and vote "out" the 3rd (potentially correct) AoA, and determine this as a single failure, hence you may not be able to directly override the ensuing protections. A major part of the unreliable airspeed drill is to potentially resolve the issue of the lone ASI being the correct one...
The 2nd scenario is essentially the recent OEB. However, the probability of 2 AoA probes going into error, in a similar fashion is low (very low). The issue the OEB raised is where the AoA probes, say "freeze", and you now alter the environment such that the frozen AoA value goes from "safe" to "hazard" e.g. reflecting reduced buffet AoA at high M number. What the OEB does is give you a course of action to degrade the Flt Ctrl laws.
It should be emphasised this has occurred once (only) in all the years of Airbus FBW Ops, and in the one case it occurred, in fact the system did drop itself into Altn Law IIRC? Easy to slam the system as a result, but as we have seen, obscure, or even simple but un-envisaged, failures in more classic designs result in (near) accidents (737 AMS, BOH etc.)