I was reading this whole thread again, because it’s one of the things it interests me the most facing the upcoming Hitman 3 and this answer made me think that it’s obvious that 47 would not kill Edwards and Grey if it’s not personal or if it’s not an order. Therefore that makes me think that even if there’s a betrayal, there must be something else to ignite 47. That leaves me with:
1 - they kill Diana and that’s personal for 47 as he’s starting to be more human and understanding what he caused to Diana and how close to her he was.
2 - instead of that, Diana is the traitor along with Grey (she looks “comfortable” with him and i think that 47 has high chances of being manipulated, since he’s the most skilled hitman but he has affective problems that could led him to think it was worthwile to pursue that “searching about the past” thing) and then if 47 is alone it makes more sense to feel that he needs to get rid off of all that people (maybe olivia is his new best friend, since i think she’s also being set up)
3 - none of that happens and we never kill Grey since he dies off camera or something else happens (it wouldn’t be the first time IO discards a very high-tension plot to uncover something even bigger that’s happening behind that first plot) that makes Grey not important.
4 - 47 wants to buy IO to force them to create a remake of Blood Money, Silent Assassin, Codename 47, etc. in the new Hitman engine and he needs all the partners money so he’ll not stop until he gets it.