Vatanen already played in 2010 WHC and was a lock in 2011 and 2012 if he hadn't gotten injured. I really doubt it's too early for him.
I think Hakanpää has a chance to be that third pairing physical D-man next year (like Joonas Järvinen this year) but that might be a bit of a reach at the moment. We'll see how he does this season, I have my hopes up.
Vatanen would've already been our best offensive dman this year so he's a lock if he's available. If Hakanpää takes similar strides next season as he did this season he could be a possible pick for next years team.