https://www.polygon.com/2017/9/12/16298132/destiny-2-update-1-021-patch-notes-guided-games

Today’s server maintenance for Destiny 2 went on a lot longer than anticipated, but with it came a massive patch, a few bug fixes and the much-anticipated Guided Games feature.

This afternoon as the scheduled maintenance began to drag on, Bungie announced a hefty 4.795 GB patch, at least on PlayStation 4. You’ll need to download the 1.0.2.1 hotfix before you can get back into the game. Once you do, you’ll be greeted by a new feature called Guided Games.