Difficult to say. I don't really follow these characters much. I make most of my guesses, by using past history for reference and trying to imagine how I would do it, if I was them.
Even so, here is my best take. I don't wanna be "heh maybe yes, maybe not" so I will be decisive.
Rain is pretty likely, but not sure. I think he is a safe bet to say, that he will be included in the game. But most likely as a DLC (NRS might have said that they won't repeat DLC, but I don't think WB gives two shits what NRS says.). Still has a decent chance to skip this game as well, as they are trying to introduce more characters. Even so I am betting on YES (he will appear).
Smoke... to be honest wouldn't be surprised if he was at best an NPC. NRS excuse would be "he was in MKX already as a variation". If he doesn't make the base roster, it is safe to assume he won't be making as DLC either (the 2 time rule might play here as well). I say NO to this one.
Noob. Pretty high chance to appear judging by how story is flowing. Past and present colliding. Good opportunity for Kuai Liang to meet Bi Han once again. Certain intro between Bo Rai Cho and Sub Zero in MKX, brought him up as well. So there could be a possibility of Kronika using Noob to deal with Sub Zero's side. Maybe even his clan. I suspect, Kronika might even recruit some people to her cause. Promising them power or some shit. I say YES to this one.
Fujin. Ok. From business point of view, this would make no sense, if they made him skip this game. Jade is popular? Pssh. Fujin at this point is a community's favorite. But I am still not sure if he will appear on base roster or DLC. DLC makes more sense, as they know that there is demand for him. So by ancient rules of supply and demand, Fujin should be a DLC character. Also storywise, I don't see him doing much (judging by how story looks so far). I say YES to this one.
As for Havik. Eeeeeeeh... low chances. I would like to see him in action, but story wise he doesn't make much sense (again judging by this story, as for me he would be perfect, as war = chaos. Havik should be actually sitting on the frontlines and enjoying the view.) So I am calling it no. I say NO.
I will most likely lose my shit, if I will guess all or at least most of them right. Cause that means, judging by my guesses and certain leaks I saw in reddit... I will be flipping my table in disappointment, once I will Frost.