Does Seasons mark the beginning of story progression?

As someone who only plays with one household per save game, I would love story progression back. I loved having siblings or children move out and seeing where their lives went. I can never be bothered to play them in order to have them get married and have children, so this would be really nice for creating extended family and having them seem real. That being said, it would be completely unfair to destroy the game for rotational players so I only want this if it's optional. Grant recently said it's something they want to improve though.
https://twitter.com/SimGuruGrant/status/998945441961013249?ref_src=twsrc%5Etfw