Bungie has confirmed they're doing weapon balance in cycles. This shouldn't surprise anyone by now. The book is an easy fix all you do is set it so all rewards from the book require that the player own the book. It would bring up no issues with any other items as the book and the items are excluded from every other item currently. Meanwhile changing something like the shadowshot bug could take a lot longer. Something like that is likely spaghetti code, and thus has no easy solution without messing up something else when you fix the first thing.