Bungie removed the previous content to make room for the next new thing before in Fate 2, and this pattern will continue with the release of The witch queen in February with the removal or the “vault” of the Abandoned Extension.
This means that not only is the campaign unavailable to players, but also the Tangled Shore destination and Year 4 seasonal content, including the exotic missions. If you want to do that, you must do everything before Witch queen releases.
Fans are understandably not pleased as many have been looking at them Abandoned Campaign as a favorite, especially because it’s about Cayde. But at least Bungie will make the campaign available to players free of charge from December 7, 2021.
If you wanna see that Abandoned Expansion out with a bang, then on December 7th you can also get the Package of the Forsaken, which grants you all exotics from the expansion, the Last Wish Raid and the Shattered Throne Dungeon.
Source – [Bungie]