I would describe battle beasts as anthropomorphic beasts with cybernetic armor implants. All the original battle beasts I can think of had lots of visible "beast" parts.
I see that less so here, primarily in the chest area, where they look like just big robotic suits overtop of the beast, rather than small armor add-ons to the beast. I'm talking about the deer or the hamster for example who look, to me, like they just slipped into a mech suit. Some of them, like the Marlin, I think look pretty good and manage to hide the blockiness, others, not so much.
What are these viable "Beast" parts you speak of that the new designs do not have ?
Small armor add-ons ? Every Beast in the original line and the new line have the exact same style of body armor.
Torso/Waist/Shoulders/Wrists/Shins, with some exceptions.