I wonder: the article states that the SI unit for Kg up to this point was defined using a single object. Doesn't this definition also involve the fact that it's placed on earth, thus requiring two objects for its definition?
People interchangeably use lbs <-> kg but the actual equivalence is lbs <-> newton (N). The difference doesn't matter in the average person's life since we're all down here where gravity is homogeneous enough for most applications and people.