: Bye-bye Cortana.

Ah, I forgot the lines, that is pretty clear.

: I thought that Bungie had said that Rampancy wan't a thing in their haloverse
: so, of course, AIs are more content with their lot.

I don't remember that but it sounds familiar. I want to say Nylund first introduced rampancy as an aside, and I would think it came from something other than extensive research to the point of playing previous unrelated games; maybe it was an outdated story bible? Anyway it's been official for some time. A lot of people think the "Rampant" chapter title thing in the level Cortana in Halo 3 refers to her, although I think it's supposed to be ambiguous or misleading.

: I see Bungie's haloverse as the old Testament and 343's as the New Testament,
: two different takes. 343 has rewritten it, now you don't need to be a Jew
: and God is for everybody. We really only need to consider what 343 says.

Well, they seem to be taking pains to adhere to and integrate older canon, except for certain parts of it. Funnily enough, it seems like they don't care for the parts that stand to limit or end what they can do with the story going forward in time while having it include certain things (like combat and the Master Chief and the origins of the Spartan-IIs and Cortana and Forerunner stuff and the Covenant).

: If they contradict themselves... well all multi-author works of fiction
: are full of contradictions. Stories change depending on who is writing
: them. People forget what they said before or they change their minds when
: they think of a new, cool, direction.

That's unfortunately very true.

: I'm not thinking about revenge, I'm thinking about loyalty. What loyalty or
: appreciation did Del Rio have for Cortana? It must have left some mark on
: her that he was going to bin her - the person who saved the galaxy from
: the Flood - "Remember me? Hello? I saved the galaxy. Oh, I'm a
: defective chip. OK."

Would he even know that? Would you care what someone had done if they were threatening your ship? Would you, on the other side of it, think it represents all of humanity?

: What experiences have other AIs had? It's possible that Del Rio was just
: beyond the pale as a dick and that other AIs had wakes and wreaths. But
: was 343 setting up Halo 5's story? Setting up an AI revolt?

I don't see how they could've been. The funny thing is that's not even the problem, it's Cortana individually. I can buy that the majority of AIs would like to not die in 7 years or less, that's very simple and relatable. Cortana going full benevolent dictator is just not her style.

: Will Cortana have a change of heart? Can the Chief get to her. Can Halsey get
: to her. Halsey seems to regret her I-know-best attitude. Has she learnt
: something that Cortana needs to learn? Some humility?

I'm going to go out on a limb and say Halsey has cards yet to play and one of them will be a trump card. Some part of saving the galaxy from being crushed under the mechanical boot of the AI uprising will involve her influence and her intelligence and quite possibly her brain or a clone of it or another AI made from her.
(They could replicate the pattern of the Forerunners in their last days-- set an AI to catch an AI. They could try to make an AI just as good but without free will and task it with ending this regime. That would at least be interesting and pay homage to the old story.)
I also think it'll lean heavily on emotion at some point because doesn't it always when you're dealing with a sentient AI, and are 343i actually creative enough to not do that?