Rewriting the history, saving dead heroes, grabbing new Exotics and having a new six-player activity are just a portion of what Destiny 2 Season of Dawn will offer as Bungie revealed a pile of new content and info.
Season of Dawn will kick off with more of Osiris' dabbling with timelines but unlike with the Root Mind, this is not his mess. Technically, it was the Guardians and the Undying Mind who disrupted the time flow when the former killed the latter. Bottom line is that Cabal somehow got their Scions to meddle and now they are seeking to rewrite history in order to win the Red War.
This brings us to Osiris' Sundial, which will become the new six-player activity exclusive to Season Pass holders. Keep in mind that if you are to become a new Destiny 2 player, purchasing Shadowkeep will include the Pass, which will grant you access to that activity. Just make sure the purchase happens after 10 December 2019.
Lantern of Osiris is the new Artifact that will be available to all players. This also means Power bonus reset and new abilities to be had.
There are hints of the new Exotics that will be available with the Season Pass, such as the new Scout Rifle, Symmetry. A sidearm that is reminiscent of the Militech piece from Cyberpunk 2077 is also in the Exotic line apparently but it is currently unnamed. You can preview it on the image below.
Regardless of whether you have a Season Pass or not, all Destiny 2 players will gain access to the new armour sets that are coming with Season of Dawn. On the other hand, only Season Pass owners will get the ornaments that can be earned in the last few ranks of the pass.