One thing that's gonna be awkward. There are a lot of people who were widows and widowers who moved on in five years and re-married, maybe had a kid or two, who are suddenly going to have their spouse come back from the dead.
Somewhat more morbidly, like millions of babies are going to die of neglect because no one is around to care for them when they get un-dusted.
The more morbidly thing. I had those thoughts but less morbid.
There were probably loads of deaths because of those that were removed. A pilot get removed, the plane crashes and those on the plane die. They didn't die from Thanos but from the plane crash. Do they come back? What about the pilot? Does he just materialise in the air?