I believe that our guardian was meant to die while fighting the final battle against the witness. This seems evident by the fact that ergo sum or the sword of the traveler, was present on our grave in the corridor of time.
Now consider the vex cannot predict paracausality, meaning they wouldn't have known that Crow would wish Cayde back to life with an Ahemkara wish.
I purpose that by bringing Cayde back, Crow accidentally changed the outcome as well as the events of the final shape. The most noticeable change would have been the loss of our ghost since cayde brought it back. It's also entirely possible that without cayde, the vanguard would have fallen to the witness, thereby not being able to cover our escape once we wounded him.
Just my thoughts.
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I see what you mean but there is a slight problem, if they couldn’t predict that wish, then how were they able to see us win? Because getting in there to win was also predicated on a wish. The Corridors wasn’t just Vex tech. It was also wish magic and a ton of paracausal power. So it was leagues beyond the Vex’s normal capabilities, that’s how we actually altered time. Which means what we saw in there, no one else has. I would follow the logic of the Dark Future lorebook, whatever that scene was only based on a possible future where Crow didn’t make the wish. Just like we would have lost had any one person made a different choice along the way. It was never a future set in stone, there never has been. We make our own Destiny.