Hi,
The System could also provide good news to the crew. 
May be (the System) should ASSERTIVELY inform to a hard working crew submitted to uncertainties (as in Thiells B727 and AF447) IMMEDIATELY when the Air Speed (and related indications) became reliable again.
IMO UAS and Reliable Air Speed (RAS
) should not be programmed by Designers as a System "inside information". Better to communicate BOTH.
The anomaly came from just the sensors (OBSOLETE). Not even (caused) from ADM, etc.
The confidence in the System (of great importance) MUST BE PRESERVED!
("Good news" in Easter day
)