From VG247: “As always, there are new Exotic items up for grabs in Season of Opulence, one of which is tied to the latest Destiny 2 raid.
The Tarrabah Exotic SMG is the latest addition to the Destiny 2 Exotic list, which is exclusive to the Crown of Sorrows raid. Two other Exotics, Truth and Lumina, will come later in the season with their own unique quests.”
Source: N4G PC Destiny 2: Season of Opulence – Exotic gear