I don’t think warm-up sketches and unfinished pieces fall under “awesome art” but art is subjective.
I’m pretty sure that any form of drawing can be called art, but I’ll avoid sketches in the future.
I just though they were pretty neat.
Also I’ve never found any colorized version of these drawings so either Bruce Timm was just making some SW doodles for fun or this is from some cancelled project.
To make up for me ignorance though, I offer this piece of awesome (“finished”) art;