Those look like stylized shuriken to me, which gives me the inkling that that could actually be Bi-Han, seeing as how Noob Saibot is never without his trusty throwing stars. Not 100% certain, though.

Link to picture

I dunno that it's anything significant. This Sub costume just seems to have glowing parts decorating it, like he has little lights on the nose area of his mask too.

If you're talking about the medallion on his chest, that's just the Lin Kuei emblem.
Otherwise, I'm not sure I know which medallion you're referring to.
Edit:
I completely forgot about that fatality.
Edit 2:
Oh. Still seems like they're just shuriken to me.

Kind of interesting that they only provided high quality images of scorpions costume, almost as if they didn't want us picking up on details.

..And I know I'm reading in to that heavily

A long shot would be to guess Lin Kuei ninja-stars. With Cyber-Sub having them loaded into his chest, maybe they thought it was time either Scorpion or Subzero had some sort of throwing weapon aside the spear.

Doubtful but it's my only guess.

Not the Lin key emblem. I am speaking in terms of "if" the thing on his belt is another medallion EDIT: Lin kuei auto correct sucks

Maybe if they used his old MK 2 snowbomb fatality, the shuriken is like explosive? but he will cover it in ice and then throw it?
I always thought that fatality was awesome and wouldnt mind if they put that in.

I honestly wouldn't doubt it. Remember human Cyrax in MK9? He had those bombs on him, and he uses it. Maybe it's like that, or Sub-Zero has a shuriken in his moveset.

Icing shurikens to throw them looks good.

Sub-Zero tends to have problems against projectile heavy guys as his own projectile fires too slow and is a combo setup instead of a damaging move.

If he had a projectile attack it could help a lot with his strategies, but honestly I think this is just decoration.

Btw, many things in that trailer can't be trusted 100%. Scorpion on the HQ render doesn't have the chains mounted on his forearms for example, and also lacks the sword on his belt (probably for simetry reasons on gameplay).

Im sure they are going to show this all monday!
I know its only 2 days but damn I wish it was today.