I guess Hasbro's hand is behind this, and I don't blame it.
Arcanopunk or magic technology is possible in D&D but they are too expensive to be used usually in the battlefield.
Sometimes I imagine D&D arcane spellcasters creating the equivalent of flywheel energy storage (this is technology from real life, not sci-fi speculation). Theses machines could be the end of the chavalry....if enemy spellcasters don't summon gremlins to sabotage this magic technology.
It is curious, because the template for petitioner in 3.0 was broken but I miss it because they could be a good hook of new stories.
In the setting the souls can't be used as fuel for infernal machines, but more like "motor". Better to be used as muscle than as food. Other option spent "soul coins" aren't destroyed really but those come spirits come back to their plane.
* Let's imagine you are an ordinary soldier in the battlefield from a D&D world. The enemy has created a war machine moved by "soul coins". These are the spirits of sinners in penance, the supernatural version of galley slave. When the penance ends the soul is forgiven and can go to the celestian planes, or an reincarnation in a superior/stronger race. How would you feel? It would be like looking a dress by human skin.
* There was a movie "blood car" about a motor whose fuel was blood, but It guess it would easier to create biofuel from vegetables or farming vermins.
* The lifeshape technology is canon in Dark Sun. D20 should to be ready for the biopunk, technology by living tissues, like the weapons by the tyranids from Warhammer 40.000 or the yuuzhan-vong from Star Wars legends (now they aren't canon). Don't you remember the gun in Jude Law's hand in the cover of "ExistEnZ" movie?