I have not looked into this, but my understanding is that the old Miss Dior was to be discontinued, while the flanker Miss Dior Cherie was to be renamed simply Miss Dior. Old Miss Dior smelled rather different than Miss Dior Cherie, and was nowhere near as successful. So the formula of Miss Dior Cherie shouldn't have changed, and you got what you were looking for. You shouldn't worry about age. Perfume lasts a long time if not exposed to direct sunlight, so your bottle will be perfect and will remain so for decades long as you keep it away from sunlight. Ideally, you should keep it in the dark, like in a drawer.