Since everyone is going to be knee-deep in Endgame discussion this week, and SW talk will likely be sidelined, I want to post an overly-wordy theory as to how I think TROS will play out. I'm guessing this'll be like pissing in the ocean since it's AEG week, but maybe someone here would want to follow up with a theory as well so we can look back and see if any of us get close after TROS hits theaters.
To me, the ST has been the story of Ben/Kylo in much the same way that the OT had been of Anakin/Vader. In these two trilogies, Rey and Luke represent the heroic catalysts who shape and determine how Kylo and Vader ultimately end up. The cool thing about Palpatine being involved now (even as just a hologram sentinel - like he is in the novels and comics) is that the ST will be a part of something even bigger. But the roles of Kylo and Rey are still the driving points of the ST story within the saga, so those two and Palpatine are the key to figuring out how TROS might unfold.
Kylo's place in all of this might be made clearer by the unveiling of the Knights of Ren. I envision them as protectors of some sort of order named "Ren" that would be a lot like the Sith (maybe even connected *to* the Sith). It would probably be named after some ancient dark lord from the Unknown Regions (where Snoke is from - and he's the only one who has mentioned them). Kylo Ren would've been named as such because Snoke expected him to become the latest version of the original Ren. And the Knights of Ren were to accompany and protect Kylo as he gained his footing. They may have even been planted as students in Luke's academy in order to secretly help turn Ben Solo.
Perhaps Palpatine/Sidious was himself perceived as a descendant of Ren in the Unknown Regions during the reign of the Empire, and had thus secured the loyalty of people like Snoke. Palpatine uses this loyalty to his advantage to create a Contingency plan for rebuilding the Empire (if it were ever to fall) in those Unknown Regions. He records his plan, and uses a holographic version of himself to communicate it to those who will execute it (as we've already seen in novels/comics/Battlefront). Snoke eventually becomes the leader of this new movement (the FO), and singles out Ben Solo to carry out the Ren legacy. To Ben (and to Palpatine), it would be fulfilling the intended Anakin/Vader legacy (which might all just be the same thing anyway).
After Anakin/Vader's death, Ben Solo represented the next in line because Luke could never be turned. Luke would then remain the main obstacle - and the main target (as we saw in the premise of TFA) - after he trained Ben to learn the ways of the Force. But much like Palpatine had done before, Luke Skywalker would be underestimated. He has grown more powerful since becoming one with the Force, and will help undo all of Snoke and Palpatine's schemes. Luke will guide Rey, and help her fulfill her destiny. She will return to Ahch-To and recover relics from Luke (probably off screen during the time jump). One of those relics will spark the search for the new MacGuffin that will take up much of the TROS plot.
As explained in TLJ, Rey is the answer from the Light Side of the Force to meet the new challenge from the Dark Side (Kylo). So, I think she's a child of the Force, much like how Anakin was presented to us in TPM until we learned that Palpatine was behind his creation (that's official now, right?). If Palpatine could create Anakin, maybe Obi-Wan and Yoda created Rey (both of their voices are heard in her TFA Force vision, which might've been a clue all along). Rey is thus incredibly powerful and incorruptible. Unlike Luke, there is no conflict in Rey (because there is no Skywalker blood in her
). Her scumbag parents (to be poetically opposite of the kind and loving Shmi Skywalker) probably didn't know what to do with her, and may have even been frightened of her because they knew her conception was unnatural.
Rey has a higher calling, and her path is being laid out by the Force itself. When she encountered the lightsaber at Maz's, that was truly - as Obi-Wan put it - her "first steps." She was seeing the saga unfold, and learning her place in it. Rey is literally the Living Force, and she will carry out its will. She will triumph (duh
), and will extinguish the Dark Side threat that is being carried over from Palpatine. She will also play a pivotal role in the redemption of Kylo, and thereby ensure that the Skywalker name will always be associated with ultimately choosing the Light Side. Rey will go on to train a new order named "Skywalker" that will use the basic principles in the ancient Jedi texts, but enhanced and improved by lessons from the example and legacy of Luke and Leia Skywalker.
That's where I think we're headed. And I'd love to read anyone else's predictions/theories - or thoughts on why I'm wrong - in case any of you guys get AEG fatigue.