I have my own theory (and sorry if I have some mistakes. English is my third language). I think that Kim has enough businesses and she just isn’t interested in continuing being associated with this game. That’s the reason why game characters (especially Kylie and Kendall) aren’t updated. Even Kim still has her old looks…
Honestly I like that diamond boxes cost 15 diamonds now. Before that sometimes I ended up opening a lot of boxes and got dyes or tickets. And I spent more than 15 diamonds. So now at least I am guaranteed to get some clothes🙄