BGQ
Not necessarily. ..it would appear the legal challenge in this case is about what you describe as "objective justifications". If one is being objective,in this case, evidence from Chile New Zealand Australia Canada Japan and a few other countries show that there is no increase in incidents or accidents by "Professional Airline Pilots" over 65 in those countries. Studies done in the US measuring general aviation pilots up to the age of 79 which tested landing or not decisions in low vis in simulators confirms what we all "know" to be true .... that performance deteriorates with increasing age.
Just to save you actually researching this yourself, Objective Justifications for a compulsory retirement age, are not exclusively restricted to justification of physical health, or mental deterioration as we age.
Purely as an example, two of many such justifications (currently) accepted in law are, inter-generational fairness, and preservation of dignity. Don’t shoot the messenger. I’m merely explaining that is the law as it stands today.
On a slightly different topic. It is crystal clear that seniority systems are most definitely ‘de-facto’ indirect discrimination on the basis of age. I don’t see any OJs that would allow that form of discrimination. Seniority systems survive in some places, only because (bizarrely?) nobody in such a system has yet tested the law.
Of course I accept testing the law is all the current litigant is trying to do.