Machinbird,
This is an interesting theorie !
@Bearfoil has also suggested this as a possible cause for the ADR disagree.
Technically that seems to be possible.
Looking more empirically at it, there have been multiple incidents with pitots freezing over, causing ADR disagree and subsequent disconnection of A/P and A/T.
However I'm not aware of any instance where an Airbus (or any other airliner for that matter) flying on A/P at cruise alt has ever all of a sudden developped such an attitude that would cause this assymetry.
Besides that also the RTLU setting would mean it had to stall/spin at M0,8.
The more likely connection to AF447 is that the pilots might have re-engaged the A/P to early and the A/P held the plane in a deep stall all the way down.
The intriguing part of this is that I was seriously wondering how you would deep stall a conventional tail airliner all the way down to FL 0.
You would probably have to pull the stick (or mis- trim it full nose-up) until the splash. When you are manually flying a fully mis- trimmed airplane it would feel/react strange. You should notice a very different aileron reaction at a stall AoA.
But if Otto's at the yoke and tells you everything is fine you might not notice it.