Court documents gleaned from Halo composer Martin O'Donnell's case against Bungie and Activision reveal that Destiny's story arc was "significantly changed" from the original, and strongly hints that Activision is responsible.
When the first chapter of Destiny's five-part franchise launched in 2014, gamers found that it wasn't the intergalactic opera they were expecting. The story elements were (and still are) very light and players finally understood what kind of series Activision and Bungie have created--the kind of piecemeal bits that can be strewn out over a decade of releases. But Destiny wasn't always like this.
The court papers of Martin O'Donnell's lawsuit against Bungie show that the game went through a phase of "substantial revision" which led to the first year-long delay. "Although Destiny as planned for release in September 2013, the story was substantially revised beginning August 2013, requiring a new release date of March 2014 and edits to much of the work previously completed," the documents read. "After a brief vacation/sabbatical in early fall, o'Donnell returned, worked on the story and recorded dialogue, but wrote no additional music. For reasons unrelated to O'Donnell's performance, the release date was again moved, to September 2014."