One thing worth being aware of is the degree to which fiction and reality are woven together across the entirety of this particular story. After all, if you've read or listened to professional authors speaking about the craft of writing, there's actually a lot in the story that starts to ring familiar. When Oberon, for example, speaks about there being both periods of inspiration (where one's writing seems to flow from the imagination) as well as periods of frustration and struggle, and moreover, when he speaks about looking back and finding difficulty differentiating the periods of inspiration from the periods of struggle, that's actually very true to the experience of professional writing. Similarly, one can speak about the frustrations of rejection as well as of self doubt. Even if it's fictional, at the same time it conveys a very profound truth.
That being said, the lines do seem to really start to blur in the ending of the story, which takes on a much more allegorical and symbolic tone than what came before, when Oberon burns his short stories and the entire city is set on fire. In this moment, the tone of the story does seem to shift toward a more fantastic quality, but here too, Hawthorne seems to be trying to convey a truth about the craft and art of writing and how artistic success ought to be measured. Oberon's despair is in his inability to be heard, but in this moment, he has been heard, and his work has, symbolically, been sent into the world. This symbolic meaning is expressed in the story's closing lines.