Engineers long dead

Apologies if this has already been a discussion post, or if I have missed things in the trailers that would suggest otherwise, but...from what I've seen, I think the Engineer/SJ are all long dead, and what we see in the trailers are only holograms played back when David activates their technology. I also think that it is David being enclosed in the SJ suit and it is David flying the derelict spaceship in the end scene where the Prometheus rams it.