I'll address each of your paragraphs in turn:
1.) Re: CS0 vs. CS1. Like you mentioned, I was very upfront about the methodology for this analysis. And I am very aware that most CS majors do not ever take a CS0 course. But please also be aware that there are a minority of CS majors that do take CS0 before moving onto CS1, usually because they feel ill-equipped to take CS1 right away. I harp on this point because even though this is a minority population, it's a very important one since those are students who, without CS0, would not major in CS. These students are more likely to be female or from underrepresented minority groups. On a related note, a larger and larger fraction of non-CS majors are taking CS courses because they recognize the value of programming and computational thinking. (Again, these non-CS majors are more likely to be female and from underrepresented minority groups.) So I would argue that CS0 is just as important as an "introductory programming" course as CS1, if not more important, due to the rise of the non-software-engineers-who-want-to-learn-programming population. [Edit: And I think that a CS department's choice of language to offer to the CS0 student population is still very significant, and a decision that is not made hastily.]
2.) Re: Python CS0 and Java CS1. You are absolutely right, and in my original article, this sentence appears in the discussion section: "Some schools have fully switched over to Python, while others take a hybrid approach, offering Python in CS0 and keeping Java in CS1."
3.) Re: AP exams using Java. Thanks for the clarification. I will remove "it's unclear whether that will change anytime soon." from the article.
[Also, as to cyorir's comment that the chosen data may have been cherry-picked, please rest assured that I tried my best NOT to cherry pick. If I had cherry picked, wouldn't I have made Python look even better? ;) Any incomplete data is strictly due to human error or oversight on my part, and I gladly welcome any correction requests via email.]