Locormus
Can we please get the older, old forum back?
I think you set your hopes too much high over this Dedenne battling thing. I'm sure it just attacks Chespin one time or twice and make it faint, without any official battle or an intense battle.
The point is that so far when Bonnie attempted to use Dedenne in a fight, it was napping. This will likely tell us a bit more about Bonnie as a Pokemon user then you're underestimating here.