LawAbidingCitizen
Bomb Setups & Ball Rolls(Mileena/Cyrax)
No, he's not been shown as part of the main story mode, nor been confirmed to be canon otherwise. So far he's just an added DLC, a means to an end to use the variation system in MKX to make the cyber ninjas playable.
Wether Triborg is Canon or not,
It's debated. I'm of the opinion he is. Others would argue he isn't.
There's no reason he shouldn't be in my opinion. I'm aware, as DLC, he made no appearance in story mode, but that's not something exclusive to Triborg. Tremor didn't appear in story mode either, no one debates if he's canon. (Not to mention Goro, or Kenshi & Rain in MK9. Skarlet had a background cameo, at least, but otherwise no presence).
He's a non-guest character on the roster, with an arcade bio, a legitimate backstory set within the overall narrative and an arcade mode ending. Those are pretty much the only criteria that made a character canon before MK9. Why should they not apply now?
He's more fleshed out than characters like Meat or Blaze were when they debuted. Hell, he's already more fleshed out than charcters like Reptile or Jade or Noob were when they debuted.
Why would he not be canon?
I know some people dislike the concept/idea behind his backstory, but... that doesn't invalidate said backstory.
In an above post I provided his backstory:
Summary of it is, Triborg is basically the leader of the Tekunin which is part of the story mode, current timeline and took the mantle from Sektor. All of the Lin Kuei was forced to put themselves in the database and it was saved and hidden. Tekunin is the Cyber Initiative which is what it was referred to before in older MKs.
All in all I feel there is plenty to make Triborg canon I think the problem is most don't realize Triborg is the head of the Tekunin and as we can see it's a big part of our story mode just from what we have seen.