I don’t think of gameplay features in terms of how old they are or to which pack they belong, but rather in terms of relevance. Is this feature relevant to the story: Yes/ no?
For me it’s not important if a pack was released 8 years ago or 8 days ago. The use of a pack specific feature entirely depends on my Sims’s narrative.
For example, none of my sims owned a restaurant as long as I have Dine Out installed. But they do visit the restaurant. Perhaps in another story one of them will actually own a little bistro. If that’s what their character does.
My game is a story world, so whatever is added hopefully blends in with the rest of the content. I stir it like a tasty soup, add a bit of seasoning, add a bit of this, add a bit of that and if it tastes right, I suppose that’s a job well done which makes for an enjoyable gaming / story session.
