"Canon"/"Historical" Old Generals - Do They Live Long Enough to Play?

As the title states, do they? Is there an in-game trait or ancillary that prevents them from dropping dead after age 60 due to old age? If there is, what is it? May plan to apply it to some custom chars....

No special traits or ancillaries - and it depends on what you mean by "live long enough" and which characters you are referencing. If speaking in general terms for the more aged generals, which is about 45-55, they will live into their 70's and 80's. So even the oldest starting characters will be around for 300 or so turns.