You can expect new Destiny 2 content following the introduction of the Beyond Light expansion. In this expansion, players will have the opportunity to wield darkness like a weapon, adding a new element to their arsenal in their relentless struggle against the hordes of enemies who seek to take over the solar system. Due to the amount of content available in the game, Bungie developers need to shrink things down and lock down older items. However, since they plan to secure portions of Destiny 2 content elsewhere, he wants to bring back the old ones from Destiny 1, like the Cosmodrome.
The Cosmodrome is a return area where you can explore Destiny 2. While it was only briefly available in the Festival from the Lost and Shadowkeep Expansions, it will be a new location after the Beyond Light expansion, which releases on September 22. This is when you can expect the Cosmodrome to return with the two strikes from the original game.
You will need to purchase the Beyond Light extension to access this content. However, since it does return content, don't expect it in Destiny 2 forever. Much like the old content items, it will eventually revert to the Destiny Content Vault, where Bungie plans to rotate the content items. It allows players to access old frameworks in the new Destiny 2 engine, and remove older parts of the content readers have explored since the launch of Destiny 2.
Two more expansions are expected for Destiny 2, Witch Queen in 2021 and Light Fall in 2022, the latter being a working title. You'll likely see pieces of Destiny 1 content returning to the new Destiny 2 game on the regular at the start of each new season. The start of seasons will not only mark new ways to play, but also introduce new places to explore, a new series of strikes, and more ways to return in Destiny 2.
Bungie will be using the Cosmodrome and the Vault of Glass raid, as a way to experiment with old and new content so that players feel like they are receiving a new experience at the start of each Destiny 2 season following Beyond Light.