- Changing tables and stuff to do for infants
- More child aspirations
- Milestones
- Social compatibility
- Multi-purpose lots (let's call them "rec centres")
In other words: Most features from Growing Together should have been base game updates - especially the infant stuff, because without the pack, they're just smaller toddlers with barely any gameplay. San Sequoia could still be sold separately as a world kit for all I care.
Other than that, as an astrology fan, I'd like to see zodiac signs patched in. They don't even have to do anything in the base game alone (because, you know, unlike infants they're not actually life stages), just a setting in CAS would be fine, a base for various DLC to expand on, similar to the already existing lunar phases.