User blog comment:Rejuvenation/Anime error?/@comment-1332195-20091209105336

I know it's a filler, and they do tend to take more liberties in those, but I don't think this is the first time he's been seen doing it in stories outside the conventional canon. Maybe it's a pointer to him showing the skill in the manga fairly soon (I hope so, anyway).

Kenny's always looking to get stronger, and improving his skill in shunpo, while against his usual m.o (like with kendo), gives him another trick up his sleeve against stronger opponents.