I can clearly see that D4 developers are somewhat inspired by The Witcher 3 in terms of storytelling. That’s a VERY good sign. I’m pretty sure that the quest where you choose “the sin which bothers you most” will have a HUGE impact upon the final ending of the game and upon the story. That’s a very smart move by D4 designers. Making a fine Diablo game with a story which surpasses in quality The Witcher 3. Wow. I’m impressed.
I think it may very well be a Telltale kind of scenario, in which characters will remember our actions.