https://www.polygon.com/2017/10/20/16512374/destiny-2-seasons-bungie-season-two-rewards-twitchcon

At TwitchCon today, Bungie explained how Destiny 2’s concept of seasons will change the game on a regular basis, and revealed what players can expect when the game’s second season rolls around. The developer also detailed changes to what it calls “rituals,” like Iron Banner and Faction Rally, and confirmed the return of The Dawning, a holiday-themed event from the original Destiny.

Bungie said it added seasons to Destiny 2 to give players “a more predictable cadence for content updates.” Currently, the studio expects to have four seasons per year, though that is subject to change. Seasonal changes will see certain cosmetic items, including the contents of Bright Engrams, being swapped in and out. New seasons will also “change the themes of the player experience,” Bungie said.