He should be better than the vast majority of kids there. I see little to gain by playing against a bunch of kids that you're substantially better than.
I think it's nuts to suggest the NHL season doesn't matter much. Maybe from a win-loss perspective, sure, but the NHL is where our young guys are going to be doing their real development. Chytil has way more to gain developmentally playing against NHL players and even practicing with his NHL team than he does playing against 18 and 19 year old kids, half of whom play on total garbage teams.
Playing for his country, playing in a leadership role, all that, if he develops (which he will do best in the NHL), there will be plenty of opportunities for that down the road. I mean he played for his country last year in the WJC, a bunch more U20 games, the EHT, and got time in the World Championship. Another U20 tournament isn't going to do anything for him other than maybe provide some fun memories.
He has, to me, established that he is an NHL player and he should only be playing in tournaments with NHL-level competition. No kiddie tournaments.