I hereby present a Stud.io MOC recreating the updated look for Steppenwolf in Zack Snyder's Justice League:
It is supposed to replace the build from https://brickset.com/sets/76087-1/Flying-Fox-Batmobile-Airlift-Attack which was based on the theatrical cut. It still uses the old Steppenwolf head (photoshopped in) but even though the details of that head piece are accurate to the theatrical version, proportionally it matches the 2021 version quite well. It's also the only Lego Steppenwolf head in existence anyway.
For the skin color I used white like the head piece. Unfortunately the 1x2 plate with three teeth does not exist in LBG or silver. The small model also has some waist articulation through the use of a Mixels joint and it uses the same build as the official Lego set for the axe, as that did not change in the film. Though here I've added a bit of the energy emanating from it to create a bit more visual interest as the color scheme of the figure is more monochrome.
I may make some renders where he's posed. Please share your thoughts and criticisms in the comments :)