Well, I'm not exactly sure what we mean by requiring flexibility here, but I would certainly agree that our flexibility with respect to what's a disease and what's normal aging are related.
To put this another way, I would say "effects of disease D" and "natural effects of aging" are both social constructs, and that the psychological/cultural constraints that cause some pattern of observations X to get tagged with the first label also inhibit X from getting tagged with the second label.
None of which really has a damned thing to do with whether people live longer healthier lives, so to the extent that we care about that, we may do better to not get caught up in worrying about these categories.
There are a lot of diseases which are different enough from aging to make the distinction more than a social construct: infectious diseases, congenital abnormalities, etc.
But yes, you can say: this is the ideal stable state, I want to maintain it forever, whatever causes it break, be it disease or aging, is bad and we want to fix that. Sure.
Google's announcement, Time magazine rather sensationalist headline.
In any case, it's nice to know that Google set its sights to "challenge ... aging and associated diseases". Apple's Tim Cook:
For too many of our friends and family, life has been cut short or the quality of their life is too often lacking. Art is one of the crazy ones who thinks it doesn’t have to be this way.
One more step towards "world optimization".