It is a likely case that the planet could very well be LV-426, as it is the only planet beknownst to the franchise as the only planet with a SJ(Space Jockey) crash. Granted that the landscape and positioning of the ship doesnt seem linear to how we found it in Alien/Aliens, the film was heard to be based very far from the timeline of Alien. Alongside that, we never saw the whole ship topple in its final position, yet the Alien ship appeared as a crash, And it is highly doubtable that a rolling over SJ ship could topple on its bottom and appear to of crashed.
Secondly, The idea that the Space Jockey(SJ)/Engineer(E) mix could very well be a twist in the film. However, i am more into the whole idea that the E and SJ could be different as the SJ exterior was made of a form of bone (Example Given Below)
I am also very speculative about the apparentness of Shaw being pregnant with an alien. shown in the analysis, shes all bloodied, weak and so on. The Alien is known to be the only Monster in the world capable of such a life cycle, unless it could be an earlier version of a xenomorph...or something possibly worse.
I dont wish to convey my further ideas on what else the trailer could show, but i hope in a sense it will all be explained and how the SJ's know and relate to the human race, via the large human esque statue and the human-ish engineers.