Again, this is all total speculation on my part about a story that is over a year away. With that in mind; After repeated viewings and more pondering of what we might be seeing, I think the most intriguing part of the trailer for me is the Boyega opening.

it definitely appears he's some sort of rogue stormtrooper who is in trouble, most likely from being close to discovery or capture. Something about that storyline really pulls me in. Perfect opening for the teaser. In just those few seconds there is palpable desperation and fear.

The Zahn novels occasionally touched on stormtroopers defecting and fighting for good. His novel Allegiance focuses on it. Those are some of my favorite stories and to me also the most interesting.

At one point in Allegiance there is a small group who are in a panic over being moments away from discovery and capture. It's a very tense and serious chapter.

Boyega's scene feels very much like that. Right now that's the part of the story I'm most interested in. Not because I think it's the same Zahn story (it isn't), but because that's an area of the Star Wars universe I find very interesting. A stormtrooper soul-searching and deciding they cant be part of it anymore and the hardships that defection would bring.