Really? Are we sure about that? NOBODY else except Anakin has been brought into the council without becoming a Master? Depending on the "authorised" source from which you draw your information, it states that Ki-Adi-Mundi was brought into the council without being elevated to "Master" status. DK's "Ultimate Visual Guide" still states that factoid. If you go to StarWars.com, it states Ki-Adi-Mundi is a knight. Oh, what to do?!!!
Anyhow, I wasn't sure if this has been discussed. If it has, I couldn't find a thread for it.