Probably. She would be able to spin the tale in such a way that we would perhaps sympathize more with her situation--she has always been controlled. First by her father, then southern society, her cousins, and finally, Homer Baron. If Emily were able to tell her own side, we would have answers to so many of the mysteries left by the story as it is now written. It might be a bit juicier!
I think that it would. Telling the story through the viewpoint of the townspeople as a whole helps to keep us informed of major events in Emily's life while at the same time maintaining a distance that gives us space to judge for ourselves. Because we don't know a lot about her inner mind, family, or other possible "inside track" information, we have to infer, guess, and then based on what IS presented to us (through a rather gossipy and negative viewpoint), make a judgment call. That judgment call is perhaps more negative than if we had the story told from her perspective, because if SHE told the story, she would have a chance to justify her actions, explain them, and present things in a way that would make us sympathetic with her. As the story stands now, we just hear the negative twinge of things as told through judgmental townspeople, so we can't help but be influenced by that.
For example, if she were to explain her emotional trauma at her father's death, then at Homer's rejection, we might feel more sympathetic. If she were to explain her confusion, and feeling of victimization by the town in regards to the tax issue, we might care a bit more. If she were to explain her loneliness, her difficulties, etc., we might think better of her in the end.
This same idea applies to any possible number of other narrators. If seen through Homer's eyes, we might hate her more. If told through Toby's eyes, there are other dimensions that might be seen. Either way, how the story is told, and by whom, definitely impacts our perspective of the characters and events.