With such a focus on the cosmic elements of the story I don’t know how much Ogres would really add to the Horde.
If this expansion was BC, Cata, or WoD I think Ogres should be a must but they keep losing out on their opportunities where they would make sense.
This person says this but probably wants the next class to be some cringy edgy melee class or Dragonborne.
The Tinker class has so much potential and blizzard has played around with technology for the last several expansions for simple encounter to complex raid fights.
On top of other mmorpg offering a technology class, elder scrolls online next expansion will add the Dwemer Engineer class.
It’s a trope that’s existed since warcraft rts days and vanilla wow.
Before demon hunter was announced the popular class predictions were Pirate, Demon Hunter and Tinker… we got pirate and demon hunter.
I never said I was opposed to it or that it’ll never happen. Only that I think there are other options. It’s limiting and a little boring to only ever focus on those two classes.
But in your original post you seem convinced that naga will be playable in 10.0 and a tinker is going to happen. We can safely say naga will never be playable, as historically they’ve been evil antagonists. And they have no legs.
But it doesn’t matter how cool a tinker might be. We can’t just assume it’s going to happen when Blizz has yet to tell us any scrap of info on the expansion yet. It might be tinker, it might be something else, we might not even get any new class at all. So don’t be disappointed if there are no tinkers. 
Worgen.
Mechagnomes .
Are humans who learned how to regain their sanity from a feral animal mind. Naga aren’t shapeshifters, they’re people who have tried on multiple occasions to conquer Azeroth.
Do in fact have legs! Two of them by my count.
The leg issue is for complications with our gear and how we ride mounts. It’s unlikely anything that doesn’t have two legs will ever be playable.
Same reason they keep mentioning Bards (which has 0 place in WoW) and Necromancers (even though DKs and Locks are close enough to them). People are just assuming a new class is due so they are speculating what kind. IMO Tinker is the only one of the 3 I mentioned that would make sense and actually fit with WoW.
Ogre aren’t good option for Belfs in the horde.
So your counterpoint is something that wasn’t added until cataclysm.
You do realize the Naga people were pretty much enslaved by a Old God who was using them for a single goal… that old God is now gone.
Just like how we worked with the Mantid and then they fought us when Y’Sharj appeared.
Even then, no race is inherently evil.