I want to know the answer, no matter what it is.
As FMJ stated, there may not be enough wreckage left to determine what the definitive cause was. Possibly there will be circuit boards or micro chips available to analyse but that won't provide a sequence of events, just a series of data points. They will probably be able to determine if the engine was producing power and if the aircraft was intact when it hit the ground. Whatever may have caused an incapacitation will never be determined but the pilots medical records may give the investigators some idea but those details will not be published.
I have flown in that area in conditions much worse than that indicated in aircraft much less capable than a Cirrus. Icing does not cause an alert pilot to fall out of the sky like this one did.