A lot of information has been shared during the reveal livestream for the upcoming final event.
Age of Triumph is the final event coming to Destiny and it will start on March 28th. It will not increase the characters’ Light Level cap (set to 400), but will update all raids to require level 390. You can expect updated loot, new items, some fixes and weekly features with challenges.
A new record book will be added with 13 pages to fill. There will be some milestones for players who “enjoyed” Destiny at launch (the system checks if player was present before the release of The Dark Below DLC). You will be tasked with various activities, some checked automatically if done before, others to achieve after the event starts.
There’s a quite an expansive summary of the revealed information on Reddit with some additional screenshot of the record book.