Just a basic question with no real study on the matter, just want to get the raw opinion from you guys.

Doubt it, they're young, they can cope with the extra matches.

Most countries focus on one tourney over another nowadays... there are A teams and B teams. Great example is Spain and France. Spain put their best teams for the Euro U-18 and Euro U-21 this summer while France focused on FIFA U-17 and FIFA U-20.

European youth NTs are also just not going to field their best teams for any tournament because of the number of tournaments and club restrictions. For example, Varane, Mangala and Pogba should easily have been part of the FIFA U-20 WC squad for France; but they were excused to focus on their club (and transfer in the case of Mangala).