The only kind of new area I personally think PS needs right now is an individual housing sector. However, I will assume that is a UE4 issue.
Nevertheless, once the game is put in UE4 I think there will be a lot of possibility for upping the efficiency of maps and maybe adding a little more detail in on the existing ones. For instance, i'm not sure how much of the current maps are instanced, but I bet they could use a bit more. Making the maps take fewer calculations could open up room for doing other things, I think.