Destiny is ostensibly an RPG. And it does in fact have incredible lore (albeit most of it is tucked away so that players will never actually encounter it during the course of the game). With the next game, Bungie should maybe leverage both of those facts and try to deliver a way for players to be able to consume the incredible backstory of the Destiny universe over the course of the game itself.
One way they could do something like that would be by having dialog choices, leading to more interactive conversations players want to engage in. Dialog choices are extremely common in RPGs, and they have recently started to show up in games in other genres too- look at Uncharted 4 and Titanfall 2, both of which have dialog choices.
By adding a dialog choice system to Destiny 2, Bungie give a slight psychological impetus to players to participate in NPC conversations, and they make the uncovering of the game’s story and lore a part of the game itself, contingent on how many conversations the player has with NPCs, and how the player chooses to respond to them.
I think it would be a good, and sensible, move forward. Destiny 2 is set to launch some time next year.