It's always surprising how some brand treat archieves Washburn is one of the worst in that.
I contacted them about my M12 and they basically denied that it was made by them.
I've seen your model some times ago and this kind of bolt-on neck is supposed to be the best of both world. Neck-thru sustain + servicable bolt-on neck.
It's used by some luthiers and boutique bass builders but most of the time, the neck is top mounted.
Many luthiers demonstrated that using multiple screws on bolt-on neck act like neck-tru design but again as it is not scientifically proven because it demands time and money.... well you just have to believe or just appreciate this bass as it is.
At least it's a nice quirky looking bass. Maybe it plays and sounds good?