https://www.polygon.com/2018/5/24/17390766/destiny-2-iron-banner-emote-iron-lord

The Iron Banner went live in Destiny 2 this week, the first time since season three and the Warmind expansion launched a few weeks ago. This weeklong multiplayer event offers exclusive rewards to players who participate. But the Bungie community is currently up in arms that a new, Iron Banner-themed emote can’t actually be earned by playing the mode itself. Instead, it can only be purchased from the Eververse, Destiny 2’s real-money store.

The emote will cost players 1100 Silver, which sells for $9.99, and Bungie community manager Cozmo confirmed on a Reddit thread that the emote currently doesn’t drop from any other location.