In his latest comment against the Prowl concept art, Derrick Wyatt posted the following comment.
"Eric Siebenaler from Hasbro showed me his concept for Oilslick right
from the get go. I was too busy with show stuff to give much input, but
liked what he had done anyway. How could I not like a bot with a Mr.
Freeze tank on his head and a ram skull on his shoulder? We really
consider Eric to be part of the show's creative team anyway. I'm sure
it is hard for Hasbro to coordinate everything. Since Marty Isenberg
actually wrote the Transformers Animated: The Arrival comic for IDW
himself, we consider that part of the show continuity. I got to do some
designs for the IDW comic as well. Marty also was involved with the
story for the Nintendo DS game. Having the show creators involved in
these types of projects really helps them feel more like they are all
part of the same universe.
There are absolutely TONS of G1 concepts that are practically begging to be in Animated. Maybe some of them will get to."