An emotive subject indeed, pensions ultimately are not going to be worth what they were sold as, just a fact of life, and for those who have been either prudent or lucky enough with finances, then they'll have the choice of retiring early if they wish.
Others, like many have said would prefer to carry on working for longer, if they are fit and able, then there is no reason to. Taking any active fit person and grounding them (aviation or other) can have worse results, I know of an a/c engineer now in his 80's and still working a full week on engines, his knowledge is phenomenal as is his work, if he stopped, I wouldn't see him lasting long doing nothing at home.
So, why not take that vast pool of knowledge and hard won practical experience and keep using it ? Let the younger generation come up and take the left seat, but use the old timers in the right to pass on the wisdom that one day may come in very useful. Do it on a one year rolling contract, subject to all medicals etc, lower pay possibly, but good perks and benefits, and offer them the option that when it comes time to hang up the hat, if they want to carry on in a ground roll, ie training, then let them...
Paperwork, Procedures and Theory don't always beat age, wisdom and experience ...