Or being creative

Seriously kid. You're connecting the most insignificant things and making them look important. Bungie explicitly stated at E3 that FoaF was not in the game at this time. Also, in a pre-release ViDoc, Bungie mentioned unique weapons "like Fate of all Fools". Implying that it was exotic. Plus, the Stranger's Rifle looks exactly like FoaF because it's just reskin for now.