At first, everybody's wrong. And then they figure it out after the Widow has more or less trashed the office, thrashed the people and threshed the documents as if they were wheat. (See what I did there?)
The truth is that even if comic characters like Steve Rogers, Simon Williams (who?!), Clark Kent, Bruce Wayne, and Oliver Queen die and come back, they are no longer the same people they were. Their fears of death have mutated. And their fears for their loved ones are even more complex.
The reason for this is simple. None of them died thinking, "Hey, I'm a key franchise character, they won't kill me." In their comic-book world, they died while being heroes or villains or whatever. They had no thought of coming back, they never took it for granted. Their resurrections weren't expected, nor taken for granted after the fact.
But moving from a state of not fearing (or thinking about) death to one of having experienced death, and then being alive again — that is a mysterious return from that "undiscovered country, from whose bourne no traveller returns." It is even more so for Steve Rogers, the victim of two deaths and several clonings as of the present time.
Not for nothing did the iconists and semioticists deliberately confound death and transfiguration. If death grants humans a reversal of life, is the reversal of death necessarily the same life? It would appear not.