Destiny 2: Season of the Deep May Focus on a Sunset Location

gamerant.com:

In Season of the Deep, Destiny 2 players may get to return to an old fan-favorite location that was sunset during the Season of Arrivals. As the Lightfall DLC progresses further and players unlock more and more quests, lore, and background information, so too do they discover hints about future content releases, and major reveals may well be underway.

The idea that Bungie may use existing Destiny 2 content to heavily hint at what's coming down the line is hardly new, as the developer has admitted to including various tidbits of vague lore only to draw upon it later on. One of the most prominent examples of this is Nezarec himself: a Disciple who was hinted at during the very first year of Destiny 2, only to get propelled into relevance with the seasons leading up to Lightfall​​​​​​.

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A Destiny leaker has reportedly been informed that Bungie may use the Season of the Deep, Season 21, to reintroduce Titan, the moon of Saturn. While the leaker in question isn't entirely sure of the information's veracity, the idea is corroborated further in the game itself, where the final screen featured as part of the Winterbite exotic glaive quest specifically mentions that there's an «enemy of Witness on Titan.» The potential return of Titan would perhaps be handled in much the same way as Destiny 2's Haunted Leviathan was, which means there's precedent for mid-season patrol zone releases.

There's also the matter of the title of Destiny 2's Season 21. Bungie itself officially revealed that Season 21 would be known as Season of the Deep ahead of Lightfall's release, and while the «Deep» is often just another in-universe name for the Darkness, the title could very well be a double entendre