It's pretty annoying how they handled that. I think we all know at this stage that the sync back up with the movies was never going to happen, but that doesn't mean AOS couldn't keep doing it's thing seemlessly skirting the edges. Taking their story that they did actually have the plot outline of Endgame but couldn't act on it because ABC wouldn't commit to when the series would air at face value then they screwed the pooch by not having the reveal that they didn't return back to the prime timeline at the end of the time travel arc of the season before keeping them out of the way until Endgame had premiered for sure.
Really is a shame the Marvel TV/Marvel Studios infighting played out as it did, AoS would have been perfectly in place to explore the consequences and initial stages of the snap.