things they can do to improve their ability in their position. By continuing those practices they learned/adding it to what they already do they can become a more capable player. The 7 on 7 is merely a small part of the camp. Part of it is to allow them to apply what they've learned in a simulated game experience, sure, but they'll get plenty of opportunity once the season actually starts. Otherwise it's for coaches to see what kids can do and to get a better look at them.
Anyway, my point is if he didn't get as much playing time in 7 on 7's this year, all is not lost. What's important is he learned something that will help him improve and be more capable.