None because they’re all terrible.
A tinkerer is just a glorified engineer.
A bard would be completely useless. Seriously what would a bard even do that any other class already can’t?
Dark rangers are just hunters without a pet and they’d be locked behind more elf races.
LET’S GET NECROMANCER on the ballot! I vote necromancer
Bard is the coolest option for me, however I don’t feel like it fits into WoW in the way that I would want it to. Bard is meant to be a true support class which the WoW meta has pushed out literally since classic.
Death knights are already here
BARD!!! I want bards so badly. I’d roll one in a heartbeat.
They’re different though are you going to tell me shadow priests are warlocks now
As awesome as a necro would be, it’s basically a DK themed warlock.
What is the difference between a necromancer and a death knight? Besides one being in plate. A DK can do all the things a necromancer can do.
And shadow priests are different from warlocks. Warlocks deal with fel energies and shadow priests tap into the void.
Did we forget about the history of Spriests being called budget Warlocks for the entire beginning of WoW?
I’m surprised how many people are getting worked up on a fake ballot, I voted necro okay.
Id choose bard of the 3, because bards are almost always a cool class in any MMO/RPG game they are in - seriously, if you never got to play the Vanguard Bard, you missed out, it was maybe the coolest class concept ever developed in an MMO…ever…So good.
TINKER
That looks like a Druid that fell on some pretty hard times.
Bard. 
Tinker.
But what I really want is necromancer.
My vote goes for Tinker. You could go 3 specs,s ranged dps, melee dps and tank (you could go healer instead of tank, but I think tank spec is better).
Now as to the question, "will blizz ever add another class?’ I don’t want to say “never” but I think it will be a very long time until we get another class.
Currently we have destro lock and fire mages, affliction lock and shadow priests, holy pally and holy priests. These all share similar concepts that are able to differentiate themselves. Except holy pally and priests, they’re extremely similar.
Also I vote dark rangers. Want a magic bow user.
Yes but aren’t hunters bows already enchanted and they use magic, anyway?
I don’t think blizzard would be able to make them different enough to warrant them being a class… especially if it’s locked behind more elves.
A dark ranger is literally just a hunter without a pet.
Dark rangers are cool too. But would they steal powers from hunters and rogues?
Dark Ranger, to be honest. I don’t think Bards have much of a place in WoW, and Tinker’s could be interesting, but I’d go with Dark Ranger above everything.