https://www.gamespot.com/articles/destiny-2-server-going-offline-today-for-maintenan/1100-6453666/

Destiny 2's servers will be taken offline today as part of the deployment of the game's next hotfix update. Here's what you need to know about the downtime:

Bungie also warned players that it may bring back the server queue after the maintenance period, presumably because a flood of players will be trying to log in at the same time.