I saw the effects of moving the retirement age from 60 to 65. It certainly slowed down progression for younger pilots and for some was quite infuriating, BUT to stay on after 60 was that particular individuals prerogative. Do I agree? Not really but that's the situation.
If the retirement age was relaxed completely, then it would certainly suit some, but I would have grave reservations. I have seen first hand the reduction in mental capacity and reaction time from some more 'senior' pilots. It is a fine balance between this and the advantages of their extensive experience.
If I was a betting person, I would say that it will be down to an AME to decide, however we all know AME's that will sign a certificate BEFORE they have examined the individual.
I do feel that there are certain jobs that REQUIRE an upper age limit, ours being one of them. Working in B&Q is not exactly the same.