That said, I'm not sure I agree with your precept that a junior title ultimate doesn't mean all that much. I'll have to think about that one.
IMO, it only means something if the victory itself means something important. Yu-Na Kim winning Junior Worlds in 2006, ahead of Mao Asada who won the Senior GPF and defeated the entire Olympic podium at some point during the season, was a significant Junior World Title. I don't believe that being "Junior World Champion" in and of itself puts you in any higher regard than placing top 10 at Senior Worlds.