In one word, absolutely.
What is art, teaching, pedagogy, anything without content? Without a meaning behind it? Content is the core of creating. If there were no content there would be no creation. An emphasis on content is necessary for art to 1) be created in the first place 2) be something that is both enjoyable and teachable. The pedagogical aspect of creation and art is derived from content. Pedagogy requires content. Content is required for the realm of art education to even exist, let alone any type of education.
Every piece of art ever created means something different to every person who sees or experiences it. Emphasis on personal voice is crucial, because without it, what is art ever going to be besides something nice to look at? Perception is unique to each person, and emphasis on learning personal voice on the receiving end will eventually develop into a personal voice on the creating end. If personal voices in the artistic world didn’t exist, all art would be the same, uninteresting things. Emphasis on a personal voice for each student and each artist invites an individualistic pedagogical approach, whereas content is a more group based educational experience. Both are crucial and deserve emphasis in the conversation of art education.