Beyond Light saw the introduction of a controversial feature in Destiny 2: the Destiny Content Vault. In essence, Bungie took away content in the game to keep Destiny 2 from becoming a completely bloated mess. On the one hand, this made the game's install file smaller and vastly reduced the development time required for creating and/or fixing new content in Destiny 2. On the other hand, activities and play areas beloved (and in most cases, paid for) by players became inaccessible without any guarantee of coming back.
With Witch Queen on the horizon, Bungie is breaking the bad news early with regards to what content will be vaulted next. When Witch Queen releases in February, Destiny 2: Forsaken will become vaulted. This includes the Forsaken campaign as well as the entire Tangled Shore. The Dreaming City, as well as The Last Wish raid and Shattered Throne dungeon, will remain.
Bungie says this is to make room for all the new content coming in Witch Queen, which will include the return of a classic Destiny 1 raid, two previously-vaulted PvP maps, a remixed PvP map from the original Destiny, and of course, everything promised in The Witch Queen reveal.
Most of Year 4 will also become vaulted, including the Presage and Harbinger missions. However, some Year 4 content will live on. Both the Proving Grounds Strike and Battlegrounds activity will live on as part of a new "Vanguard Operations'' playlist that will be free to all players. Warden of Nothing will also stay and be free to all even as the Tangled Shore retreats into the DCV.
As for Spider's illicit operations, Master Rahool will take over as Destiny 2's currency exchanger. What this means for Spider remains a mystery, but it's probably nothing good.
To soften the blow somewhat, Bungie is providing free access to the Forsaken campaign. All players will be able to play through perhaps the best campaign in Destiny 2 absolutely free. However, access to Forsaken's Last Wish raid and Shattered Throne Dungeon (and their associated Exotics) will remain pay-to-play content courtesy of a new Forsaken Pack.
Access to Forsaken and the Forsaken Pack starts December 7 and lasts until Witch Queen's arrival on February 22.
The Forsaken Pack will also include three Forsaken Ciphers that can be used to instantly unlock the non-raid, non-dungeon Exotics. For those who already own Forsaken and its associated Exotics, Bungie will give away three Ascendant Shards on December 7.
One thing worth mentioning is that Bungie said they were "investigating ways to reprise and create new exciting Exotic special missions within Destiny 2 for the future." While this likely refers to Hawkmoon and Dead Man's Tale, this also opens the door to Whisper of the Worm and Outbreak Perfected, two Exotics that also arrived as part of their own specific missions.
If you haven’t played Forsaken, definitely take advantage of this free giveaway as it will provide Crow’s crucial backstory and whatever awful thing happens to Spider.