Everywhere you look, it's always going to be Shazam. I did not like it when Captain Marvel was renamed Shazam. It makes it more confusing, simply because most people won't get it. They will ask, "Wait, but if he says Shazam to make himself change and if he tells somebody his name is Shazam, won't he change back?" Yeah, that is it.
It should be Champion of Shazam as marketing. Hell, that would make a good film name as well, to use because I want him to be Captain Marvel in the film. That would be excellent, for Captain Marvel to appear as that around the same time as the release of Marvel's Captain Marvel movie. Since people don't really care for the female Marvel, only Mar-Vell, it would be a slap in Quesada's face.