They’ve already recreated a story mode for Ghost Play which is FANTASTIC and adds lore and meaning to the game.
How about adapting the same theme of NPC missions for live mode and giving players a valuable item in the game as a reward?
For example: a fisherman NPC who gives the player the best fishing rod in the game in exchange for ghost fish and tells them their story.
The rewards should be attractive enough to want to have them in every game and should have a connection to the NPC in question: for example, a chest or backpack with more storage, a portable radio for the vehicle or phone, a money tree, etc.