https://www.gamespot.com/articles/iron-banner-makes-destiny-2-debut-with-these-gear-/1100-6453826/

Destiny 2 has already seen the release of several Trials events that spice up the Crucible PvP scene, and soon we'll have the game's first Iron Banner event. It's coming quite soon, as Bungie has announced the limited-time event makes its Destiny 2 debut on October 10 at 2 AM PT. It will run for one week, and unlike the original version, Iron Banner in Destiny 2 works differently.

Iron Banner matches will be 4v4 affairs, just like other Crucible modes, and features the Control game mode. Bungie stated that your "fighting abilities, not your power levels, will decide the outcome," so it sounds as if Power levels will not be taken into account. Standard Iron Banner ranks and bounties are also out and have been replaced by Engrams.