These kinds of issues are easily resolved with communication. Coaches select a team of their best players and all should be informed of their role in the team. Some may be informed that court time will be limited, for a reason, this is fine if players know.
Problems arise when coaches don't communicate, yes it was an elite level of competition, but the kids are still young and development will take years for some, more than others.
I see both points of view, however under 16 age group is still very broad with respect to maturity and physical development in the body of the athlete, not to mention their minds...
The experience is the key here and a great one it is to be involved in. Character is revealed!