I mean.... Yes? Both.
As stands, and I realize this is controversial on this forum, Tinker is a very obvious missing class with a robust fantasy currently not overlapping significantly with any existing class and quite substantial grounding in the setting. I'm quite partial to the often floated idea of a D.Va like Tank spec (God I miss OW1), a more alchemically inspired Support/Healing spec like the Alchemists in Motherlode, and some sort of turret-y DPS spec. But I also don't see us getting this class until The Last Titan at the earliest.
But I am also VERY strongly on the side of more Specs. The absence of Earthwarder Shaman tanks is still heartbreaking to me. I am also a big fan of the idea of a Battlemage Tank spec that utilizes all 3 schools of Mage spells but defensively (also being built around having a 1h and a Staff as an off-hand Gandalf style). Obviously DHs really want a new spec as well, I would personally have it be Ranged (or Evoker medium range) with heavy blood theming and call it Sacrifice.