The Dragon bone katana uses the wrong materials to craft. It uses star metal instead of dragon bones to craft.
The Dragonebone Katana is a DLC item, for visual purposes.
It is the equivalent of an Epic Katana crafted with Star Metal, but with a cool dragonbone appearance.
Not a bug afaik.
Not this discussion again… 
I think the “bug” is in the vague item description.
And it still has debuff like other dragonbone weapon. Maybe it is bug, actually.
Does it apply sunder?
If so, that needs to be reported as a bug yeah.
It applies sunder, yes. Another reason Conan Exiles is P2W