In the new Justice League movie, we see that:
Superman is revived by being placed in a Kryptonian Regeneration Matrix.
It is pretty understandable that this can be explained to the public, as one such event has occurred in Batman v Superman: Dawn of Justice. This is pretty easily explainable because he is not a human and many things are still unknown about him.
Having said so,
With the death of Superman, Clark Kent was also dead and we see a detailed funeral service. When Superman came back, how do they explain the return of Clark Kent, who is assumed to be just another human being, working in the Daily Planet?