Looking at NHLe this season so far, Puistola is behind 8 forwards who were invited to camp. It's not a perfect method, but it gives a rough estimate to compare across leagues.
He's behind Lundell, Jarventie, Parssinen, Nikkanen, Puhakka, Helenius, Hirvonen, Lambert.
Ahead of Simontaival, Aaltonen, Mantykivi, Korhonen, Pyyhtia, Petman, Valkeejarvi, Raty.
Hard to speak on how the coaching staff wants to build the roster in terms of offensive vs two-way role players, but based on scoring alone there really isn't much reason to have left Puistola out of the camp. He is about middle of the pack in terms of the guys who were invited to camp, plus the obvious fact that he's a returnee who played well at WJC last year.