My guess as to what Season 6 may entail:
1. Kreese and the female sensei (Kim Da-Eun?) form an alliance and take back Cobra Kai. There may even be something romantic there as she seemed to have a crush on Kreese as a young girl, but I'm not sure the show would go there.
2. Some of the Cobra Kai students (Kyler, Kenny, etc) may rejoin under new management or they recruit students from Asia or internationally to join Cobra Kai.
3. All of the students (Miyagi-do, Eagle Fang, Cobra Kai) spend most of the show training for the international tournament (Sekai Tekai?) and then compete in it.
4. Miguel proposes to Sam and she initially turns him down, but she may accept later in the show after the tournament.
5. Tory becomes pregnant with Robby's child. This ties in nicely to the whole fatherhood theme percolating throughout the entire show. This also solidifies the bond between Johnny and Robby because both can help each other through fatherhood. Tory also has to make a tough decision to withdraw from the tournament.
6. Regarding Carmen's pregnancy, and I hope they don't go there, but maybe she miscarries seeing that she's probably later 30s early 40s. Kind of cruel irony with Johnny preparing for fatherhood, but he can now face the new challenge of preparing for grandfatherhood. And maybe they spend the rest of the episode trying and she gets pregnant again around/after the time of the tournament.
7. Silver pays his way out of prison. You don't really think Terry Silver stays down and out for long, do you? He likely feigns remorse and tries to ally with Kreese again. Or a battle ensues between he and Kreese for the dojo. This battle may be mental with each man trying to gaslight, manipulate, or outwit the other despite outwardly cooperating to train CK students.
8. Hilary Swank returns as Julie Pearce and she throws down with the female sensei from CK. She also helps to train the Miyagi-Do students some of the methods she learned from Miyagi.
9. Chozen reconnects with Kumiko and we get more Chozen flashbacks.
10. I don't think they do much more with Mike Barnes. If anything, I have the sense that he rejoins Cobra Kai because he seems easily manipulated and someone like Silver can do the trick.
11. Hawk mentors Anthony. A way of redeeming himself for the whole fiasco with Kenny. Oh, and Anthony takes to Chozen's training (or maybe Julie's) better than Daniel's.
12. Robby wins the tournament. He's always been the runner-up so it's his turn.
I'm sure most of this is completely wrong, but it's just one person's random predictions