>>132891064Homura is not the protagonist. She is not the focal character, it opens with Madoka and not Homura, and you are meant to empathize with Madoka's objectives and emotions, not Homura's--at least until the very end. Homura is a very clear deuteragonist as Rebellion demonstrates with the change in roles.
At best you could argue that Madoka is a false protagonist and if so then given the nature of such a twist, it would be expected that the title not give it away.