https://www.polygon.com/2018/8/3/17645570/destiny-2-forsaken-year-one-weapons-random-rolls

In this week’s This Week at Bungie, the studio revealed the fate of Year One weapons. Many Year One weapons and armor will be retired in Destiny 2’s second year, making them completely unavailable to players who haven’t earned them yet. Players eager to have everything in their inventory only have a few weeks left to complete their collection.

Bungie clarified which weapons and armor will be retired in September. The Year One weapons and armor will be removed from Vanguard, Crucible, Gunsmith, Meditation, Trials of the Nine, and Iron Banner vendors when Forsaken is released. The emblems given out by the Gunsmith, Meditation, and Cayde-6 stashes will also be made unavailable. Cosmetics and seasonal rewards for Vanguard, Crucible, Trials, and Iron Banner vendors are also entering retirement.