Faulkner was a man who felt like he wanted to create stories that was something totally different than what anyone else has seen. He broke many of the rules in English and it would not follow a plot line. Every chapter would be different from the next and every idea would not be coherent with the last one. But in at the end of the book the reader will have the full picture and that is what makes Faulkner a great writer.
Writing to true form of the southern writers is a hard thing to master. "A Rose for Emily" does not really match a southern story. While there are valid traits of southern writing one can take from think story it is not an overall Southern story. Though the story may take place in the south it is not important because Faulkner wanted the reader to get a creepy vibe at the end.
Typically southern writers are very big on family, manners, and place so it would be unlike them to leave you feeling this way at the end of the story.
One can argue that Faulkner in fact does represent Southern writings because of his many families that he created are based off the aristocracy of the South. This can go back to his grandfather being in the Civil War and dying for the South. Faulkner could have written them way he did because the events that he partake in gave him a reason for liking the south.
While Faulkner writes about the Old South writers like Mason write about the new south. In the new south many people have gotten ahead of themselves and just are not driven like they used to be. It has become hard for them to do the easiest things because the do not feel it will better their lives in anyway. The old south was very into making a living for yourself and working hard to get it these differences can be seen if you read both stories then compare them because they wrote in different times.
Faulkner leaves the reader feeling a sense of what he can really give to use at the end of his stories because he will never reveal too much he will just cover the bare minimum and leave the reader to fill in the holes which makes him great writer.