Despite weather not seeming to be planned for KSP2, it could be fun to have planets windy atmospheres, with jet streams and the like. That would pose a nice challenge.
Far easier to implement would be having composite / non-spherical asteroids or comets, like 67P Churymov-Gerasimenko or Arrokoth. It would be more realistic for Kuiper belt objects and a lot more fun to explore and take some screenshots!