Content from older packs need to be slowly integrated into the Base Game

I became aware of this when I saw many simmers wishing for a band-themed pack. A band doesn’t just include a guitarist and a drummer, but also a singer. Therefore the singing skill needs to be brought to the Base Game, so there won’t be a need for a new singing skill in a newer pack (which would make things complicated) or we wouldn’t need to leave singers out from the band pack.
With "Get to Work" being one of the first packs to release, I'd wish to see the careers come to Base Game, to the actual gameplay features (actually working in live mode), but only the jobs themselves. So we can have police officers, scientists and people in the medical field in the Base Game (especially because police, nurses and doctors are pretty basic jobs), same would go for veterinarians for example.

Please post more of examples like these, whether it’s gameplay/CAS/BB.