Battle 1 predictions
Soma/Isshiki/Megishima vs Kinokuni/Julio/Pokemon Trainer (PT)
For the first match I think Soma and Isshiki will win, and Pokemon Trainer guy/girl will against Megishima.
At first I thought that maybe Isshiki would lose, that was when I read the spoilers for chapter 209, before reading the actual chapter, but now that i have read the actual chapter I don't think there's a way he loses against an opponent that alright insulted him, plus now we have backstory material for Isshiki.
Why do I think Poketrainer will beat Megishima?
Because we as readers don't really care too much about Megishima, we are probably getting some backstory in the next couple of chapters, explaining why he left Central etc etc, but ultimately he's a bland character, out of all the rebels is the one we know the least about.
If Poketrainer beats him he will get hyped, after all he would have beaten the 3rd seat, so Poketrainer would then become a powerful opponent to be beaten by the main 4 (Soma, Erina, Megumi, Takumi)
Soma would have already beaten Kinokuni so I don't think he would face PT, I think the one to fight and beat him will be Takumi.
If my predictions are correct that would leaves us with:
7 rebels:
Soma, Erina, Megumi, Takumi, Isshiki, Kuga, Subaru
6 central:
Eishi, Rindou, Momo, Somei, Eizan, Pokemon Trainer.
Battle 2 predictions
Takumi/Subaru/Kuga vs Pokemon Trainer/Eizan/Eishi
I get the feeling that Takumi's match will be Takumi/Subaru/Kuga vs Poketrainer/Eizan/Eishi, here's why I think it would be something similar to this.
One thing about this is that since Pokemon Trainer would have already fought in the previous match, maybe he won't fight, in that case I think either Momo or Somei will fight Takumi and Takumi would still win.
First I think that Takumi/Subaru are gonna be paired because of their rivalry. As I said Takumi and Poketrainer would battle, Takumi WILL NOT lose on his first match, I could even see Megumi or Erina losing on their first match, though I don't think it will happen.
The only way I see Takumi losing would be if he somehow gets paired against Eishi or Rindo, everyone else should be game for Takumi.
Subaru vs Eizan, Eizan has to win his next match, I generally think that in manga, especially sport manga (And let's face it Shokugeki is practically a sport manga at this point, at least in format) - you don't want a hyped character to lose twice, Eizan could lose if he doesn't fight a fodder Rebel. If Eizan loses his first match though he would practically just be a comic-relief type villain from now on.
As an extra prediction: Subaru will probably help Takumi with his dish at some point, thus providing some sort of help that will likely make a significant impact in Takumi's dish.
Kuga vs Eishi, it's been foreshadowed and I think Kuga will actually get his rematch, and if there's one OK way to make a character that has already lost lose again is by pairing him/her against an overpowered opponent, in this case Eishi.
Kuga vs Eishi will probably be a typical match where Kuga's growth is shown and will actually make Eishi sweat, but ultimately Eishi will win.
5 rebels:
Soma, Erina, Megumi, Takumi, Isshiki
5 central:
Eishi, Rindou, Momo, Somei, Eizan
Battle 3 predictions
Soma/Erina/Megumi or Soma/Megumi/Isshiki vs Momo/Somei/Rindou
After that I think the teams for the rebels can either be Soma/Erina/Megumi or Soma/Megumi/Isshiki, ultimately I think it would be the first since Erina wouldn't have fought yet and I doubt she wouldn't (finally) have a cooking match. I think their rivals would be the remaining Central that haven't fought: Momo/Somei/Rindou (In that particular order of fights)
If it's the first match-up then I think Megumi would lose against Rindou, if it's the second I think Isshiki would lose against Rindou.
Tbh I just think that Momo, Somei, Kinokuni and the new elite 2 are practically fodder, they were basically made to be beaten 'easily' by the Main characters, Eishi and Rindou are the real threats, and Eizan should get a win because he should probably be stronger. Obviously one or two of these fodder characters will probably get a win, most likely against the rebels' own fodder characters: Megishima, Subaru and Kuga.
I won't speculate any further here, it's extremely unlikely it will turn out this way anyhow, but I think the remaining characters would be this after Battle 3.
4 rebels:
Soma, Erina, Megumi/Isshiki, Takumi
3 central:
Eishi, Rindou, Eizan
Battle 4 predictions
Erina/(Megumi/Isshiki)/Takumi vs Eizan/Rindou/Eishi
Basically a set-up for a Soma/Erina vs Rindou/Eishi match.
2 rebels:
Soma, Erina
2 central:
Eishi, Rindou
Battle 5 predictions
Soma/Erina vs Rindou/Eishi
I think this match can go two ways:
1.- It's a normal Shokugeki with 2 individual results for each contender.
2.- It's a 2vs2 Shokugeki. e.g. The same ditch is prepared by Soma and Erina and is tasted against the dish made by Eishi and Rindou.
If it's 1 I think Soma and Eishi will beat Rindou and Erina will lose to Eishi, thus the final match would be Soma vs Eishi.
If it's 2 Soma/Erina would win the match.
Battle 6 predictions
Soma vs Eishi
Soma wins.
Extra prediction: We get a BLUE world cup arc in WSJ or Shokugeki no Soma finishes only to continue on Jump SQ, I somehow think Shokugeki no Soma could continue, but WSJ tends to 'cancel' their sport manga once they reach certain point, and you could consider the Regiment de cuisine Shokugeki no Soma's National Tournament, and by the point these matches finish SnS would probably be around 28 to 30 volumes long, which is pretty long.