User blog comment:Xilinoc/Ch. 577 - SWORD/@comment-11446176-20140416080500/@comment-957629-20140416124511

"Untrue" is a bit of an overstatement, it would not be the first time a Shikai or Bankai has changed!! Ichigo's swords have changed many times over the series and he's the only one consdered on the same level in terms of uncontrollable Reiatsu!!

Sealed Zanpakuto appear as Katana, basic Asauchi so Kenpachi's sword was released but it was only partially released in some form!! He stated himself it was always released but he did not know its name, we know from Renji and from Ichigo that learning more from your Zanpakuto can easily change the appearance and abilities!!