Regarding previous history of probes and issues with reliable airspeed indication.
From the Aus news release ...
At the time of the occurrence, {Easyjet flt Japan to Australia} most of the operator's A330 pilots had not received unreliable airspeed training. Most of these pilots had transferred from the operator's A320 fleet, and the third-party training provider had not included the topic in its A320 endorsement training program, even though it was included in the aircraft manufacturer's recommended program since 2004.
That's five years slip in a recommended topic for training and an agreed addition of a topic to a training syllabus. By training, does this mean classroom training, or do they mean incorporating this into simulator scenarios and simulator events for flight crew? The info is sparse in the article. The difference between simple ground training and awareness, and applying this info to a flying scenario in a crew training device would include the time and money to make a formal training course modification, complete with academic, software, and procedures validation steps to be taken.
As each of them costs money, and given third party involvement, a requirements statement, SOW, and a contract (or contract mod) eventually agreed cost in time/effort/materials between parties.
Is five years too long for this to take for a change (for upgrade training? not sure what endorsement training means) or is five years within one sigma of standard industry deviation?
When one has a known systems issue, or in this case a systems difference issue, getting that knowledge into the hands of the aircrew in a usable form probably gets prioritized along the lines of "how critical to flying safety is this particular knowledge element compared to others?"
How is that determined? Standard risk management/mitigation process?