Does Seasons mark the beginning of story progression?

I see no reason why we can't have SP as long as it does not affect played families with a turn off SP option for those who don't want SP and a button to pass on NPC's that have serious romantic relationships with played sims. One of the reasons I use the MC commander mod is for SP were NPCS get married and have babies, it makes the game more nicer to play and MC commander SP by passes played sims families.