This could very well just be me overthinking things as I tend to do often, but ill share anyway lol

So we have Jacqui and Erron Black, one Special Forces and one who, while not Black Dragon, has some connection to them. He could still be seen as an enemy of the Special Forces though since he sided with Kotal Kahn. Not to mention in his dialogue intros it is heavily hinted that he kills people for money, his ending implies this as well. So technically he can be considered a criminal, and therefor an enemy of the SF.

First these two have an interaction in the comics, nothing too notable, but Jacqui does beat the hell out of Black.

Then we have their intro dialogues, where its quite apparent that Jacqui is not an Erron Black fan, she flat out states she really doesn't like him, and Black just not caring.

Still, not that big of a deal. Although, I feel like those little things coupled with a few endings could possibly be foreshadowing something.

Now I know endings are non canon and we don't know which ones will be used or referenced until the next game but bare with me.

Lets start with Erron's ending, where he jumps the SF younglings and kills them all, this obviously wont happen, but the place/situation is very similar to another ending...

Now we are at Jax's ending, which shows a very similar scene to Black's ending, the SF kids are about to board their transport but instead of Mercenary Black killing everybody, Jax manages to deflect most of the shots himself, but is hit, and slips into shock as a red stain grows on his chest.

Now we get to Sonya's ending, and in short, its stated Jax was actually killed...by an assassins bullet.

I wonder who that assassin was... possibly Erron Black? He is stated to be a mercenary in Jax's ending and lets be real, there isn't a huge difference between an assassin and a mercenary.

IF it comes true that Erron Black does kill Jax, that will sow the seeds for revenge. Jacqui already doesn't like Black based on intros, and if he kills her dad, then she really wont like him. Wanting to take him down will probably become a huge thing for her, which would probably lead Jacqui and Erron to have a Sonya x Kano like relationship in the future lol

Like I said, probably just overthinking things as usual, but its fun to speculate