In its quarterly earnings call this afternoon, Activision confirmed a "major content" release for Destiny 2 later this year, on top of the second expansion already coming in May.
A "major content" release will likely be akin to Destiny 1's "The Taken King" expansion, which released about a year after the original game and was larger in scale and content than the first two expansions. It will also most likely not be included with the game's current Expansion Pass.
Activision CEO Eric Hirschberg confirmed during the call that Destiny 2 player engagement indeed declined, but Activision and Bungie want to address player feedback to bring them back into the fold.
Most recently, Bungie released a content road map detailing upcoming additions and fixes coming to the game in an effort to drive players back to the title. Some feedback has already been applied, like for next week's Crimson Days event, where there will be much less emphasis on microtransactions.
For now, though, players must wait for change and hope that the bigger expansion coming later in 2018 will do for Destiny 2 what "The Taken King" did for Destiny 1 and improve the game greatly. Last weekend saw the game's lowest-ever population of players in the once-popular end-game PvP mode, Trials of the Nine.