Wikipedia is not censored. I feel a diagram, as you suggest does not do the job of a photograph. Take a look at any fine medical textbook. There you will find plenty of, what many consider, disturbing photographs. I don't know that the juvenile claim can be verified. I know a woman well into her twenties with a similar looking vagina. It seems appropriate to have a picture without pubic hair since it offers a better view of vaginal anatomy.  
Wikipedia is written collaboratively by volunteers from all around the world. Visitors do not need specialised qualifications to contribute, since their primary role is to write articles that cover existing knowledge; this means that people of all ages and cultural and social backgrounds can write Wikipedia articles.  2nd and 3rd paragraph. It would be great however if a gynecologist were to contribute. this may be falsely assuming that they have not.  
It seems that it would be an honor to any contributor if teenagers were to come on here to learn about vaginas. This seems far better than going to questionable pornography sites that are just as available.