That's a little odd of a claim. The Penguins already have Letang, Marino, Ceci and Ruhwedel as RD, so Friedman slots in as the #5 RD. They also have 5 LD who have shown they're NHL caliber (Dumoulin, Pettersson, Matheson, POJ and Riikola), so they already have a logjam on defense.
I don't really know much about Friedman at all, and he doesn't have a lot of NHL experience, but I honestly don't see a roster spot available for him without another trade. I'm a little confused here.
It's not unusual to see GMs go with players that they're familiar with. It's not inconceivable that Hextall views Friedman over Ceci/Ruhwedel or at least will give him a chance.