I think Propellerpilot is correct. In the absence of any data and cockpit recorder on the PC12 I doubt whether the official report is going to be much more than speculation.
They should be able to tell what configuration the aircraft was in at the point of impact and from the damage to the airframe, what the impact forces were, but how it got there and the thought processes that led to it being there are gone forever.
Pratt and Whitney's best are not immune from failures. A PC12 in Australia recently suffered an engine failure at night over remote country. Fortunately the aircraft has a massive glide range and the pilot (female, for those who earlier questioned why there were two female pilots on the fatal flight) was able to reverse her track and glide back to her departure point. The cause of the failure was due to a maintenance error by some people who should have known a lot better.
For those who think they are a slippery little beast, the normal approach is around 90 knots and they can do it slower still if needed. They have an enormous flap span and from memory they are Fowler flaps. They could almost be classed as category A for IFR purposes.