I can't find the exact source, but I recall hearing that Kevin Fiege said anyone who was in a potentially dangerous situation upon unsnapping, such as in a plane, wouldn't appear exactly where they snapped from, but instead the nearest safe location.And everyone who was in the air on planes. I think the figure is that at any given time there are a million people in the skies. And everyone who was on a boat. Or in a car and just appearing on a major highway.
Yeah even if Endgame brought everyone back, several million of them died immediately upon returning.