Another problem with breaking things into smaller individual pieces yet is it wouldn't likely be coded for cross play; that is across packs. You notice that when they add a new feature, it's often limited to the world that came with it. Like you can't take your jet ski and go back to earlier pack's water, the trash system is only in Evergeen, etc. The game would be so much better and more bug free if there was just one big world, or at least if everything came together so everyone's game was the same. A lot of the bugs I'm sure come from this not knowing situation of what pack setup the new pack is going into. I've spent hundreds of hours mucking about in the coding, and there is SOOO much extra in there that is often never used. Like even if you don't have the werewolf pack, there are lines and lines in each world's code to make werewolves show up. And lines and lines for events that no longer or rarely happen (like the concert, day of the dead, etc). Breaking a normal pack into two or three pieces would make all this even worse.
BTW, EA, I would happily shell out for one good sized world that you could do it all in. I tend to play in just a world at a time as it is, and it would be great to have a world you could do the Sulani things in the waters, have an eco system, be able to put my high school there without mucking around, take walks and ski and such as in Koromebi, etc and on. It would have to be a pack that came with those things, but tying all the game has had to offer together in one place is long overdue.