It seems like rather than these sort of well defined periods of life and death ... solar systems go through a whole slew of possible life cycles where who knows what happens.

I remember learning about our own solar system and it was largely "here is how we got to here" but now it's more about these phases each planet experienced and maybe will experience. Saturn's rings being a sort of "recent" phenomenon and such. Geological activity being a sort of on and off thing depending on various events, even orotundities for life cycling on and off.