Cortana asked because the Official Story is always a fabric woven of an uncertain mixture of truth, wishful thinking, and outright lies, and she doesn't know the lay of the political land well enough yet to tease out the relative percentages herself. The more versions she hears, the better she can triangulate on what really happened. She's also currently pretending to have more respect for privacy than she actually does, at least until she determines how best to pull her usual shenanigans on the information infrastructure of the 31st century. It's frustrating but strategically sound, and it means holding off on digging for the Real Story on her own.

Fortunately, all that backstory takes a split second to tell at computer speeds. Cortana's pause afterward is the exact AI equivalent of a confused blink. It's not often you find out something that makes the Forerunners look straightforward. And it doesn't occur to her to laugh at "COMPUTO." She was created by the military. A not insignificant fraction of their time is devoted to coming up with dumb acronyms.

"...Right." As far as Cortana knows, there has never been truly untethered AI in the extremely long history of her galaxy. Not to mention Babbage hadn't ever used the r-word, which she'd think would have factored extensively into an AI-driven war. "Our situations are, ah, not analogous."