Okay imo:
1. Boys grow a lot taller than they are at 15 years old.
2. Even if a lot of teens reach their almost adult height before 15-16 years old there are still other visual differences.
3. This game cannot implement other visual differences (face aging, body hair and other things that seperate teens from adults) so the game has to rely on height to create a visual difference.
So imo, no. Teens being as tall as adults is not a good thing in the Sims because there is no other way to tell them apart for sure and it makes children going from looking 8-9 years old to 17-18 really weird.
