assuming the dark below is real, and assuming its about the south seas here are 5 reasons why shadowhunter is more likely than tinker (although it probably wont be a class if its south seas, it will likely be new models + naga for horde and something else for alliance)
1: can actually use ranged weapons like bows instead of robits
2: zandalar is in the south seas and is a huge empire while undermine has been covered in magma so refugees who dont want to fight the alliance and horde seek refuge in exchange for teaching them about their voodoo that they do. goblins are stuck underground.
3: easier to implement then battle mechs are, they can use mail like normal classes and can use bows, daggers. one handed swords.
4: can heal without shovin needles in you. good ole hoodoo voodoo is better for your blood and bowel movements then science and needles
5: would offer a unique playstyle being a mix of shaman and hunter while keepin that warcraft feel and are more established in wow lore then steam warriors are.
specs
headhunter:
dual wield melee dps. uses a mix of curses and quick stabs to kill their enemies, their blades are empowered by the loa
witch doctor:
healer and crowd control.
can heal by both granting life and stealing life from enemies and sending it to allies. can also curse enemies turning them into chibi versions of the opposite faction to insult them.
dark ranger:
using a mix of totem magic and bows guns and crossbows the dark ranger mixes shadow magic with physical blows of his arrows.
Vanity spells
Voodoo dance: dancing causes all enemies atleast 10 levels below you and all allies to become possesed by the loa and start dancing and singing praises to the loa.
lasts 15 seconds can be used once an hour
summon loa: once every ten minutes summon a loa who will tell you a fortune. depending on level and continent which loa you will recieve. depending on how many times you have died recently or won loot the loa will tell you different fortunes.
occasionally you will summon the wrong loa and he will kill you and leave you naked on the floor until you rez
IT DO GROW BACK MON!: cuts off a limb and using dark magic you grow it back. good for party tricks. occasionally you die from it not growing back in time