Nah, Tinkers are wayyyyy too broad of a concept to only be a single spec.
It’s not like Demon Hunters where Blizzard had to stretch to make it a two spec class and couldn’t even muster up a third.
The idea is as fleshed out as Death Knights or Demon Hunters were, arguably significantly moreso than either of those.
Before Demon Hunters existed, there were like 5 of them and Illidan in BC and we hadn’t heard of them for years until Blizzard decided to break the glass and pull out the “use in case of emergency” idea of retconning BC and bringing Illidan back from the dead.
Nailing down exactly what a tinker should be is damn near impossible because the potential of the class is so large that two people can come up with half a dozen ideas each and have minimal overlap.
FWIW, my preferred implementation would be the following:
Mail wearer:
Tank/Healer/RDPS.
Tank would be in a big mech, GMOD style where mitigation is done through forcefields, barriers and other such gadgets installed in the mech. “Heat” as a resource, which basically acts as a “reverse rage/RP/whatever”, where some abilities generate it (like powerful defensive or offensive abilities) and then you have to use other abilities to vent it to stop your mech overheating.
You could have self-healing justified as you (the pilot) doing internal repairs and activating emergency protocols and whatnot. As a very, very last case emergency, you could eject yourself out of your destroyed mech and call in a new one to be air-dropped in, if you can survive long enough to pull it off.
Healer would basically be a combat medic with gadgets to make it more practical. You could have gadgets like “self-applying bandages” to act as a HoT, force shields to act as bubbles, throw Health Potions for AoE healing, and so on.
Range DPS would basically be “Engineering but actually good”, all those wacky gadgets that Engineering has that have to be neutered for balance? They’re gunna be the bread and butter of the spec. Bombs, Turrets, Rockets, Mechanical Dragonlings, Lasers, basically every cool offensive toy that Engineering has had over it’s lifetime is beefed up and put in the range DPS toolkit.
Engineer would probably be a better name, but the profession already took that.
Even if we’re just porting current abilities into the game, even ignoring everything new you could do for a tinker:
They could have AoE slows/roots by putting down a gadget that manipulates gravity, maybe even makes a mini-Black Hole if you wanted to emulate a mechanic like Ursols Vortex or whatever.
Single Target res could be a defibrallator, MASS res is just this gigantic Tesla Coil that zaps everyone alive.
Battle Res is them jamming a big ol needle of adrenalin into you to get you up and going.