I have made a change to how the Random Trait Generators and the Legacy Challenge Rules work for the Sims 4. Since Teens can now roll for Aspirations that also include teen-specific aspirations along with the original aspirations from previous packs, it made sense to change the wording on when to roll for aspirations.
When a child becomes a teenager, roll for the teenager aspiration (ignore what the adult aspiration says for the moment) and go with whatever is assigned. If your teenager is able to complete their aspiration before adulthood, then you can either choose to go with a randomly generated adult aspiration from the generator next (to add some more randomness to your challenge) or do what has been done in the past and choose the next one. It’s up to you!
The rules have also been reworded to reflect this.