AI/EASA probably plays with the plates game
The history goes like:
original flat plate --> (A320) XL airways accident --> Change to conical plate -->(A330) EVA incident --> Revert to flat plate per EAD--> (A321) LH incident --> ?
The 'new' flat plate isn't allowed to be customized (= painted in company colors) and during A/C washing the AoA sensor should be covered by the normal AoA cover and additional by a sheet of transparent PE taped on 3 sides to the fuselage with colored tape. (leaving the bottom part non-taped) to prevent water ingress.