Before today, in my collection, I hold every exotic besides those locked behind quests (Legand of Arcius, Whisper of the Worm) from the base game, Curse of Osiris expansion, and Warmind expansion. That being said, I've already come across this issue before in the end of the Warmind expansion itself never having received the Borealis until last week's Fated Engram. Since the launch of the expansion, I've had somewhere between six to eight Exotic Engrams drop in the game itself, whether they be world drops or rewards from powerful/legendary engram rewards from bounties or other quests. All of the Exotics I have gotten have been duplicates, and the likelihood of that is reasonable. I already have so many that getting a Forsaken Exotic should be slightly more difficult. However, on top of the Exotics found, I have purchased both of the Fated Engrams offered by Xur thus far through the expansion. As said above, my first Forsaken Fated Engram resulted in the Borealis which did finally unlock the last Exotic in my collection that wasn't locked behind a quest. This week's Fated Engram however gave me the Raiden Flux Exotic for Hunter which I have had from before the launch of the Curse of Osiris expansion. I am unable to tell if Fated Engrams are unable to result in Forsaken Exotics, or if I am just unfortunate to receive a duplicated Exotic due to a bug. I would have rather contacted support to get an answer on this because all I see are posts on Reddit from previous expansions about people having every Exotic they could get already, but I have yet to receive any of the Forsaken expansion Exotics.