Re. to HV (post# 4154). Following your suggestion I was able to find a few ADs which seem relevant.
The most recent (2003-148) is for A300/A310 and Thales AA probes with low serial numbers; it refers to a manufacturing defect of the drain hole; and requires to perform the Thales procedure to clean/repair the probes. This AD seems very similar to two ADs isssued in November 2002 applying to Thales AA probes with s/n lower than 4760 (2002-586 for A320, and 2002-594 for A330/A340).
These ADs are in response to airspeed discrepancies reported by "an A320 operator".
I was not able to find, in these ADs, a direct reference to the increase in maintenance frequency. Also I was not able to find anything more recent from the EASA web site. I do believe that Airbus has been following this closely.