https://www.pcgamer.com/destiny-2-fans-uncover-new-exotic-catalysts-and-armsweek-event-details/

Ahead of its big Forsaken expansion, Destiny 2 is getting a smaller but significant update in July called the Solstice of Heroes. Among other things, we already know the Solstice update will bring prestige raid lairs and 6v6 Crucible quickplay. And after poking around Destiny 2's database and files, players reckon they've worked out another part of the update: a new weekly event called 'Armsweek', not to mention nine new Exotic Catalysts. 

Destiny 1 players may remember a weekly event called Armsday, where you could order specific weapons from the Gunsmith using Legendary Shards. It looks like Armsweek will greatly expand on Armsday by turning into a weeklong event and adding in unique rewards and activities.