The expansion after shadowlands absolutely needs a hero class to drive in new players and increase hype.
We saw with both DKs and DHs that it brought incredible hype and many new players to the game. Having a class start at a high level with cool concepts drove in many new players. Most DHs mains I have spoken to started playing in Legion (as a lot of players keep their mains forever and stay loyal).
I dont care if its Tinkerers or Necromancers or Shadow hunters it needs to happen to drive in hype and dreams.