Pretty good follow-up discussion on the article here. r/linguistics is a generally high quality subreddit.
I have resolved to start using they and their as singular pronouns without remorse. I use them in conversation, but always hesitate to write it. I know that those words don't solve every issue with gender neutrality, but I count them as a step in the right direction. I don't think I could adopt yo; it already has strong connotations for me that would make it difficult.
A lot of the examples given in the source paper for this article seemed very iffy on whether yo was being used in a "yo went that way" sense or in a shortened "fuck yo couch" sense. They specifically mentioned that they allowed for existing uses of the word yo when doing the study, but I wasn't convinced.
NPR seems to have stolen this article concept from this site: http://grammar.quickanddirtytips.com/grammar-yo-pronoun.aspx.