@SimsAddict_244 I could see minor weather being added to a base game (showers/light breezes) but not full on scale Seasons, and certainly not the others. Look at all the people who've posted they don't want Pets or Seasons, and those who play "normal" who don't want anything supernatural, whether it's because they think it's plum or because of religious reasons. Unless you provide a way to turn off those features in game (meaning the purchasers will be paying for content they don't intend to use).
A base game should be just that -- the basic needs for playing the game. That means world(s), the Sims themselves (biggest mistake was leaving out toddlers IMO), a good foundation of skills and careers, things to do, etc.
