I definitely think we'll be seeing a new game pack next. Based on the bundle releases, there's always a game pack and two stuff packs in each one. 'Laundry Day' and 'My First Pet' will need a game pack to be bundled with (since 'Fitness' and 'Toddlers' will most likely be matched with 'Jungle Adventure'). That being said, I also think we'll be seeing at least one or two more stuff packs as well... and then 2018 will most likely end with an expansion pack release (I'm hoping for Seasons).
This is my hypothetical 2018 schedule:
2nd Quarter: Game Pack
3rd Quarter: 1 or 2 Stuff Packs
4th Quarter: Expansion Pack