Who is the unnamed narrator in “A Rose for Emily”and for whom does he profess to be speaking?
The narrator in "A Rose for Emily" is definitely a townsperson, or the townspeople themselves.
The narrator tells the story from the point of view that the townspeople would have had when originally witnessing the events that are told about. Notice that nothing is mentioned that wouldn't have been seen or heard or smelled by the townspeople.
When Emily buys poison, we get the details from the point of view of the pharmacist. When the house smells, we get the story from the point of view of the people that smelled the stink, and from the people that put down the lime. When town leaders go to Emily to collect taxes, we get the version of the events from the point of view of the people that went.
Since townspeople never went upstairs to the bedroom where the skeleton was kept, we don't get that detail until they finally do go in the bedroom--after Emily's death.
I don't know that there is much disagreement about the narrator. From what I've read, the only disagreement that exists today is whether the narrator is a single person from the town, or the collective voice of the town itself.
It is worth remembering,when considering the voice of the unnamed narrator in the short story "A Rose For Emily", that the author, Faulkner himself, knew a lot about the small town characteristics of populations such as the one Miss Emily belonged to. Everyone has a different,subjective, view on a piece of literature, so for me, I always feel as if I know the narrator personally. I feel as if he is an old resident or native of the town retelling an old story about a town and a family whose history is common knowledge round those parts. He seems like a journalist - or a writer! - because the viewpoints of the characters seem almost like they were interviewed about what they saw, heard, smelt, visited etc.
As you say, the narrator is unnamed. Because of this, there is no way of knowing who he is. In fact, there is no way to even know if "he" is a he. The narrator could just as well be a woman. Scholars disagree a great deal on the characteristics of the narrator.
However, I think it is clear that the narrator speaks (or professes to speak) for the people of the town as opposed to Emily. I think that the narrator is most likely professing to speak for the more upper class of the community. I think that because he often speaks of Miss Emily in a sort of pitying way, as if she is higher than her socially.
The narrator is objective third-person narration. It is a vague narrator who represents the townspeople as a whole. He may be a member of the town. He presents in such a manner that connects him to the story of Miss Emily. He talks about the curiosity of the townspeople upon her death.
The narrator is an accumulative voice for what is occurring in the town. He does not give us one set opinion but represents his opinions as being those of the collective group. He does not seem to have strong feelings one way or another about Miss Emily but does share that at a later time they had pitied Miss Emily.