I don't know if the show could be described as "campy", at least in the same way that the 1960s "Batman" show was. Certainly, the show was not campy in the way that the cartoon version, which came after, was. There weren't any "super-villains", and Captain Marvel only came around in order to save the day. What I personally liked about the show was the idea that the protagonist commune with his "Elders", who tested Billy into actually solving the problem, with help from his Mentor, before he even felt the need to become "empowered". Then again, growing up without a dad for most of my childhood, I kind of empathized with the idea of these "larger-than-life" figures giving sound advice to the protagonist (though, even back then, I thought it was cheesy for the actor Michael Grey to speaking to cartoon figures in a cave...lol).
But, I've more or less stated all that is relevant to the subject. Though done, I would love to continue to read other people's thoughts on this subject. And, hopefully, whatever DC has in mind for the latest iteration of SHAZAM! will be both appreciated and expanded upon, especially if the movie does well in theaters.