Spa Day refresh
https://simscommunity.info/2021/08/03/the-sims-4-is-getting-its-first-pack-refresh-soon/ Ok. I'm surprised that they started form the best made game pack in my opinion.
Forum Discussion
Lot traits/challenges didn't exist back when Spa Day got released, so I would definitely expect some additions in that area. Other than that I'd expect stuff that would be easy to implement due to already existing mechanics, for example I don't think it would take much resources to create a spa worker active career
