Curate, connect, and discover
I think that the Power Fantasy wants us to understand the characters as they are in 1999. They know what happened, they know the world made it out alive, and thus so do we. But they also look back upon the past through the lens of the present.
We see the Tokyo event as Masumi does; an episode of dissociation, Etienne reaching out to her, and violence instilled into a single memory.
The Cuban missile crisis and New Mexico festival massacre are seen through Valentina's eyes, as remembered in the present.
The killing of the Major is seen through Jacky's eyes, and thus there is an emphasis on the violence of the act, and on the elements that will come to make him regret it. And obviously, Jacky's memories of the early Pyramid is distorted and simplified, not quasi-photorealistic like the other, more flashblub memories. Eliza is pure white.
And, of course, knowing how the crises of the past went puts us into the headspace of the superpowers in the present; neither they nor us know if this crisis is one they will get through. Compare the hypothetical linear Power Fantasy; crisis after crisis is resolved without the destruction of the world. What would mark the 1999 crises as any different?
I was talking to some people about the narrative effect of the issue #3 timeline in The Power Fantasy and the phrase that comes to my mind is "disaster voyeurism". If the story had started in 1945 and proceeded linearly, we'd arrive at each of the events on the timeline and not know what would happen or even if the world would survive. But with TPF's actual nonlinear structure, we know the world persists at least until 1999, and also that it faces these very specific crises.
I feel like that shifts the whole tone of these events. I know they're going to be awful, but I'm also really curious what happens, and the knowledge that "the world and all the main characters survive" puts a little distance between me and the nerve-wracking suspense of not knowing what happens. Someone on Discord described it as "anti-immersive"- not the exact word I'd choose, as I do feel immersed in the story in a lot of ways. But I see what they mean, in that I can look at past events with mixed eagerness and dread, rather than just dread like the characters must feel.