I like the dial. I think it's a fun little touch that most people are not even going to see when these are displayed in the majority of collector's displays.
About the fact this is a new tool - while there is no way of knowing until people start getting him, it might be likely a new tool would have been required anyway. Why? The vac-metal.
I've never seen it applied to soft plastic (probably because it might flake off.) I don't think the way the armor plugs together on the regular Hordak figure would have worked with hard plastic as it seems to rely on the pliability of the peg to fit snugly in the hole. I could be wrong, but I was thinking this might snap together differently. Which means a new tool. So the dial might be more "hey, we have to have a new tool so why not add a new, fun bit of differentiation on the back" rather than a new tool being created EXPRESSLY for the dial... which I don't see Mattel doing.
EDIT: Actually, I just looked at the back of the figure and indeed it uses the old hooked-tab method (like the classic figures) so a new tool was needed no matter what.