Yes and no.. the good nations wouldn't have too many guys at both.
Czechs would for sure and maybe Sale does both as an example.
My guess is that it doesn't end up a true best on best... lots of guys (like Nemc, Jiricek, Wright etc) will be high draft picks a month earlier and I coudl see the teams saying no to this and to be ready for camp. If that's the case, it gets watered down and becomes meanngless fast. Eg. are they seriously going to send Power after he won the World's and went to the Olympics? Same with Raymond... he keeps this up and he may win the Calder... does he really want to go to a U20 tourney when he's such a good NHL player? No idea.
I also hate summer tournaments.lol