Difficult to offer any true advice, since we cannot see the player play in question. However, just because someone has results doesn't not mean they should stop developing their game and/or technique if needed especially if they are such a young junior.
Take that however way you want, like I said with such little info its impossible to say for sure.
Throughout your life advance daily, becoming more skillful than yesterday, more skillful than today. This is never-ending. - Hagakure