Airbus is working together with the ATSB and the supplier to identify the ADIRU failure mode. Additionally, as the same ADIRU PN standard is fitted on single aisle family aircraft, Airbus is currently checking if temporary measures are also required on these aircraft types.
However initial investigation result seems to indicate that single aisle family aircraft flight control system is more robust against this ADIRU failure mode.
It seems they might know a bit more than they are disclosing at this time...