I can't see how the WJC would be a "Development" opportunity at this point in time. To develop you need to be challenged and the WJC will not provide that. He'll be playing against inferior competition two levels below where he's playing at right now, what does he have to learn from that? Nothing. Keep him in the NHL where he'll be challenged night in and night out. Six games like yesterday against Nashville is worth infinitely more in development then WJC Gold.
He's turned the chapter on his junior career, no point looking back now.