I think he is not.

I find there is a flaw in the story.  Qi Shuo is Qi Yue's son from the future.  But, he should have disappeared from the moment QY conceives a child.

A Darker Interpretation:
After five years Qi Yue is the only one who remembers her son Qi Shao. She wrote a web novel maybe to remind herself or be reminiscent of the days they spent together.

But losing her son and knowing that he sacrificed himself for her future has put a huge burden as the years go by.  And finally she has gone insane and sees Qi Shao from time to time on strangers faces.

She always makes sure to take a second glance and imagines that her dead son is alive and well, just around the corner watching over her, just as he had done all those years ago. 

I don't really watch cdramas that much but damn, this story is awesome