Anthropologically, I think that this isn't super far from what has already happened for humans. Grandmothers specifically had a lot of repsonsibilities and importance and I believe that's why they generally live longer than grandfathers.

Instead of being about career development, it's been about specializing in hunter/gatherer stuff while still able bodied.

https://www.discovermagazine.com/the-sciences/grandmothers-a...