As of the writing of this, Bungie had barely reestablished Destiny 2 servers but most of yesterday and early this morning guardias were not able to jump in the game.
Two hours after the weekly reset and the entry of Hotfix 6.3.0.5, the game began to suddenly fail and much to force Bungie to shutdown the server to rollback the changes as it became evident that the Hotfix needed a fix itself.
While the game resumed a couple of hours ago, it is being said that a faulty code or a corrupted asset was pushed on the production server and basically broke Destiny 2.
Players are expected to have their characters' accounts rolled back to 8.20am / 11.20am ET / 4.20pm on January 24, meaning several hours of progress may have been lost and that repetitive blue engram drops from enemies will be a common thing until the next patch.