@sharestuff I'll take a stab at this. I'm a science writer with a master's degree in science writing. I do interviews and report on science news and do other journalism things, but I never specifically went to J-school, so I dunno what is officially taught about advocacy.
For me, advocacy is a spectrum. You don't always have to write the call the action to be an advocate. It's inappropriate in some forms of writing, and can make you look less credible as an author. Advocacy can be ensuring the people you're interviewing come from diverse backgrounds. It can be recommending the Associate Professor as an expert instead of the tenured professor, because they've worked just as hard but may not be as widely recognized yet. It can be asking whether the conferences you attend have accommodations for nursing mothers or people who are Deaf or Hard of Hearing.
There are so many ways to be an advocate in journalism, just like in life--all it takes is some creativity.