The daggers that the reworked Katarina drops should be the same as her respective skins.
Looking at the linked video, you can see that when High Command and Bilgewater Katarina drop their daggers after using Q or W, the dagger is the same as the default skin. This should not be the case, considering that they hold different daggers compared to the base skin.
I'm hoping that that's a placeholder, since the animation for her throwing daggers on those skins is blank.
EDIT: Just read the description of the video, in that case I really hope that it gets fixed before live! Sorry for the bother.