That's a very good point about the link between this bit of background and Fenrir's eventual career as a child-biter. Starting out as a very young werewolf, coming from the background of seeing lycanthropy as a birthright and a source of pride, and then running into wizardry's marginalization of the werewolves -- it's very easy to imagine the steps filled in to give him the idea that by biting children for raising as werewolves he'd be creating a new generation of werewolves who viewed lycanthropy with the same pride he does.