It should mirror Social Security & Medicare/Medicaid retirement ages. Anything else is discriminatory.
If they can pass an FAA Class 1 Medical every six months, then they should be good to go. There are many who can't well before those ages.

Forcing pilots onto Cobra or other insurance for two years before qualifying for stuff they've paid into their entire careers is wrong. Hopefully most won't need it, but the choice should be theirs.

It's really wrong in this day and age to have age limits. That goes for FAA and other government jobs as well. If you are fit and can pass the tests and medicals, then go for it.

Do Doctors or Lawyers have mandatory retirement? Do judges? Politicians? I know plenty of cops, firemen, EMT's who would loved to have continued working, even if it were only a desk job doing administrative duty....
if they can pass testing, then why not?