Point of Nerdity: A "Murder" is for crows. Ravens are an "Unkindness" or, occasionally, a "Conspiracy".
The corvidae family has such cool collective nouns. Crows: Murder, Ravens: Unkindness, Rooks: Parliament, Jackdaws: Clattering etc.
Back on topic: I do enjoy the reluctant hero aspect and enjoy designing characters with lots of hooks for the DM to grab onto. Maybe his family does know and just aren't able to tell him. Maybe his Great-uncle Munin is grooming him for something greater, maybe he's the great-great-(etc) grand-nephew of a former Archive. Maybe some Winter Court/White Court/Black Court higher ups are thinking "Ravens are cool, let's minion-ize him!" I'm not planning on writing out his background that deeply, but there are lots of possibilities out ther.