Possibly, but the class would have to be changed from Tinker to Mechanic or something more broad. Additionally, classes tend to be uniform in terms of abilities. It would be rather odd for an Ethereal Tinker/mechanic to be shooting missiles or deploying robotic bombs like a Goblin or Gnome.
Another possibility would be an "Explorer" class based on Rafaam who is an Ethereal from Hearthstone and now a canon character in WoW;
But I don't feel that such a class would fit an expansion were Ethereals would be introduced.