Would there be a lot of detailed cutscenes? If so, then yes. It should also be about the events before your guardian came to be. Like with Kabr and his team entering the VoG, the battle of the twilight gap (like many have said already), maybe about Toland while he was starting his journal, maybe about Eris and her team going to try and end Crota or about the invasion of the earth by the darkness, with the arrival and eventual death of the traveler. There's so much awesome lore that I'd like to see more in-depth than just the Grimoire cards. Maybe even a story as about the vanguard before they were the vanguard.