Well, only three came in... Sanford F, Tuch F and Hanifin D.
I can't see any of them leaving at this point, unless Tuch happens to light it up in the second half like Kobasew did, then he's a possibility. Even then, it is rumored that Kobasew left only because he was missing his girl friend (or she missing him), not for hockey reasons. It did take him a few years to stick with Calgary.
I guess it depends on where the individual, his family/family advisor, or his NHL team think he is better off developing, at BC or minor league hockey. I'm guessing Jerry irons that all out before hand and gets them to commit for x amount of years. You don't have the success York has had building a program and maintaining it's high standard with one-and-dones. If that were the case, with the talent Minnesota has had leave after one year in the recent past, they'd be winning NC's every other year.
That being said... Eichel is ready NOW. He should sign up to play along side Sonny Milano immediately following the WJC.
mookie... get a room.