This intrigues me. The notion that Finn could still be a jedi. A full on Light Jedi with Rey being a Grey is fascinating. I hope we're headed to some such storyline.
Figure looks much better in proto photos than she did at NYCC. Definitely putting her on my list of things I want to preorder.
I think the possibility of Finn being a Jedi is still very high. They never say he's not force sensitive and Maz, who is Force sensitive, gives Finn the lightsaber and then tells him to use it. I don't see why she would do that if he wasn't force sensitive. He is also shown to break the FO trooper programming, so he's not weak minded. He appears to do this when he has his "awakening" on Jakku, which is said to be a light side nexus, in the same way Dagobah, Malachor, and Morriband are dark side nexus'.
And I think grey Jedi is where this Trilogy is going. The concept of yin and yang, true balance between light and dark, and ultimately embracing the complete view of the force is the destiny for both Rey and Kylo. Even the Force Awakens novel opens with an excerpt from the Journal of the Whills.
"First comes the day
Then comes the
Night.
After the darkness
Shines through the light.
The difference, they
Say,
Is only made right
By resolving the gray
Through refined Jedi
Sight."
~Journal of the Whills 7:477
This is supposedly the book we see Luke have in TLJ Trailer. It should be crucial for the plot going forward. And it's what Luke means when he says the Jedi must end. Fully light doesn't work and fully dark doesn't work. You need both, which is why Kylo, and now Rey, are so desirable to Snoke. He also knows the secret for full power lies in harnessing both and being grey, even if he leans moreso on the dark side.
If I had to guess how the next two movies will go, Luke will sort of train Rey, but he will disappoint her when he doesn't help her save her friends. She will confront Snoke, be tortured, saved by Kylo, and join him. Now she's off the path of light, and Luke will train Finn to save her and Ben from the dark path in IX. It's just a theory. Not completely sure if Finn becomes a Jedi through training with Luke. But I do think Rey joins Ben, or at the very least, they work together.