So I've been re-watching the video a bit and noticed something that I think is quite interesting (probably not relevant to this years Project releases, but I think it's noteworthy).
So at the end of the trailer we see our 4 Projects standing outside a city (controlled by whatever entity created the Project/Program entities), and within that city we see a couple holograms. You'd probably brush them off as just being "filler", but I think there's something deeper at work. Looking at them, you might just think that the hologram on the left is Ashe, and that makes sense, what with the hood and the bird [note: "bird" referring to her Hawkshot ability] (it just seems to fit), but you have to consider that there probably wouldn't be a hologram of a "rebel" (particularly of that size) in that city, and Ashe also doesn't use a bird in the Project universe, instead she uses a drone. You know who does use a similar bird, and who (I think) would fit reasonably well with the Program skin-line? Janna. That said, I honestly can't place who the other hologram might be. Been looking through some possibilities, and I can't figure out who fits that appearance, style and the animation shown.
Anyway, what I'm thinking is that it's possibly some kind of hint at future skins, and probably Program skins at that, if not just subtle references to help "flesh out" the Project universe.