User blog comment:Ultimantium/Original Sin: Hickman's Avengers Vol. 5/@comment-4651179-20190410213013

The Avengers issues that tied into Original Sin did so tangentially. Like most Original Sin tie-in storyarcs (if not all), the explosion of the Watcher's eye only served as a catalyst that thrusted a book's main character(s) into an unrelated story that stemmed from either them learning a dark secret, or somebody learning a dark secret about them.

What is more interesting is that in Avengers it's never explicitly stated that Cap relearned about the Illuminati because of the Watcher's eye. I'm pretty sure Doctor Strange's spell just happened to wind down, allowing Steve to fully remember, but since it coincided with Original Sin they took the chance to tie the two events together.

As for why did Hickman had the Avengers in the future be versions of the ones that travelled forward in time? Because it created a nice visual parallel (additionally, it was a world almost 50 years into the future, therefore it's an alternate universe, so he didn't have to worry about predicting the next Avengers line-up).