Slight tangent, but something I did really like about what I saw of Rebels was the concept of The World Between Worlds, to the point where I was actively wishing something similar (if not the exact same thing) would have been a major plot point in the sequel trilogy instead. Rather than The First Order trying to build another redundant, uninspired, planet-sized super weapon, one that simply blows up even more planets, it would have been so much more fun and mysterious if there was an archeological race of sorts to find, excavate, and utilize the portal. Basically, take Mads Mikkelsen's character's motivation from Indiana Jones and the Dial of Destiny, apply it to Kylo Ren, and have Kylo/The First Order obsessed with wanting to go back in time to try and wrong the rights of Vader's and Luke's actions at the end of Return of the Jedi. Then let Rey represent the whole "let the past die" thing and, thematically speaking, make the sequel trilogy more about needing to move on from the OT/PT era (while also paying homage to it). Heck, Thrawn could have even taken Snoke's place to a degree, and the whole Ezra-sacrifices-himself-and-Thrawn-to-The-Outer-Regions thing could have made for the perfect Episode VIII, Empire-like cliffhanger, only it's Rey and not Ezra.
I don't know, it's just such good drama, and the perfect nostalgic McGuffin, that for lack of a better word was "wasted" on an animated show not everyone has seen, when the sequel trilogy was in desperate need of something fresh, and this basic plot line would have been the perfect solve.
Oh well. At least it makes for a good cliffhanger/lead-in here, and I'm definitely eager to see where it all goes.