Destiny 2: Beyond Light is scheduled to release this November, and it's set to be one of the biggest revamps yet, with nearly half of the game being cut - despite this though, the update is going to require players to download the entire game from scratch when it releases.
It might not be as painful as it sounds though - given the sheer ammount of content the game is cutting, the game size is going to shrink by around 40% - so it should be a lot more manageable to download. Bungie also suggested the sleaker package will make it easier to fix bugs and work on releases closer to the wire.
Due to all these changes, Beyond Light will be a full re-download on all platforms—we know this will be painful for those with slower or metered internet connections, and we’re sorry about that. To help mitigate this, we’re planning to enable Beyond Light preloads sometime in the evening of November 9, Pacific Time, which should give everyone at least 10 hours to download before the gates open.
It seems the game engine has had a major overhaul which will allow Bungie to respond much more quickly to show-stopping bugs and other issues. While we know it's not a brand new game engine, it does seem like Bungie have addressed a lot of their technical debt.
Indeed, even your character might come through the change looking a little different, as the face building system has been completely overhauled. It promises more player customizations and options, with expansion down the road, but does mean that your Guardian "may look a bit different" once the update goes live.
The update is due to release on the 10th of November.