Story of Iron Banner/Lord Saladin
As stated before, Destiny really doesn’t combine the competitive and single player sides of the game. It’s possible that this new story could be explaining how the Iron Banner was created and the origins of Lord Saladin. He is a decorated warrior who led forces against various Fallen Houses during the Battle of Twilight Gap, so maybe we will be participating in this event.
It’s not even like Destiny hasn’t played with the idea of time before, as the entire Vault of Glass raid was based around the concept of time and moving through it. So going back to the time of Lord Saladin’s campaign against the Fallen Houses could open up Destiny to a very interesting and intense story. Powers such as Sunbreakers and Nightstalkers all existed before the events of The Taken King, so explaining how our Guardians have these powers wouldn’t be difficult. We know the outcome of this battle, but seeing how it all went down could really give the story a shot in the arm it desperately needs.