Re: post Fate of the Jedi trilogy, OT era series announced
I believe that it was introduced near the end of the New Jedi Order saga. Jaina kind of finally accepted the title during her training by Boba Fett prior to facing Jacen for the final time (I might be wrong, it's been a long time since I've read those books).
Chief of Operations
Ignoring the The Last Stand since 2011.