Those are CG renders not concept art or am I wrong?

 

Could be both. The renders used in the film had to come from somewhere, even if what people normally associate with 'concept art' is stuff that's different from the final product.

 

  Awww yeaaaa!

If you want to get technical, yes, you're correct. The images that the OP posted are official CG model renders. Typically, "concept art" would be more along the lines of illustrated concepts of characters/props/scenes etc., usually done with image editing programs or even traditional illustration methods. But for the sake of this thread/most people's intentions, we just lump them in together, since they're most often found in the same places in the corners of the interwebz.