Filament wrote...
They have a more squared jaw with a chin rather than just being a rounded sort of thing, they don't have the Homer Simpson protruding mouth
They have it actually and it's similarly rounded. You can see the protrusion on the profile shot of the genlock in the background. I even specifically mentioned it in the earlier post, too

(along with the skin colour difference which is the only real visible change imo. I don't count the ears since they're covered by the helmet so you aren't going to see any potential difference about them in the game)
and the mouth is more horizontal than perma-grinning
That's a pure conjecture given the entire (brief) section of the trailer which shows the genlocks has them with mouth wide open. We don't know what it's like when closed.
The new version does have more humanoid teeth. Does that however, combined with the skin colour, really make them more dwarf-like overall when you take into accounts all aspects where the similarity is reduced?