Kishi has always done that. We shouldn't really expect Orochimaru (with the Sword of Kusanagi) and Itachi (with the Totsuka Sword) to be the only characters with items that reference legendary items of Asian mythology. The guys Kabuto zombiefied are supposed to be the biggest badasses in history. If anybody is going to have legendary weapons, it's obviously them (unless they've been passed down, like the Seven Swords of the Mist were supposed to be).

And there are plenty of swords and weapons named "excalibur" in western fiction.