https://www.gamespot.com/articles/iron-banner-debuts-in-destiny-2-soon-with-these-ge/1100-6453826/

Destiny 2's first Iron Banner event has been announced and it's coming soon--with the usual rewards but also some changes, too. In its latest weekly blog post, Bungie announced that the limited-time Crucible event will kick off on October 10 at 2 AM PT, ending at the same time on October 17. The gametype is Control, which challenges players to ... control zones across the map.

Iron Banner matches will be 4v4 affairs, just like other Crucible modes. But as for what's new, Bungie said "you fighting abilities, not your power levels, will decide the outcome." Additionally, "Bounties and Ranks have been replaced with an Iron Banner Engram."