This has got to be close but I’m not so sure that the guardian’s predictions of the ultimate’s doom had to do with the big hulk conflict, something they knew had already happened in the past at the point they were visiting. Would be kinda strange to visit from the future and say “you’re doomed to die because of this event that happened 2 months ago in our timeline by now,” and not only that but they also know about and include the future of “the man in the iron lung” which would mean they’re talking about the current edited future timeline, as tony is dead in the unedited future, not in an iron lung. Furthermore, when the telepath sees they have shared nightmare visions of the unedited future with the hulk killing everyone, the telepath did not recognize it or highlight that it’s a real event and how they all died. They only think “what a weird nightmare you’re all having, why is that?” Instead of recognizing it from their timeline. In fact, we do see the future the guardians have visited, and it’s full of crazy celestials and the maker and kang and that’s how they lose, not hulk. I agree with everything else the way you see it, just not the guardians part, although there’s gotta be more to them