There is material here for a number of interesting story arcs.

What happened when half the world population returns, thinking and feeling as though they had never gone, while the other half had five years to try to adjust? What happens when governments make matters worse?

What happened with the super soldier program after Cap's plane went down? Did some of the subjects get treated badly?

How does Bucky Barnes adjust to civilian life in this new world, knowing his past?

They tried to do it all at once. That may have been a mistake.