If people would read the thread rather than just skimming it, they would see that the second interim report only got indications of fuel slush icing up the heat exchanger by going totally away from both the max spec of water in fuel spec, the sample taken from the crashed plane and the probable (i.e. guess) mixture based on the Chinese fuel and likely change during flight.
The AAIB cannot (or at least not publically) replicate what happened. There have been a couple of rather inflamatory press releases from other sources which do not seem to have anything to back them up other than either wishful thinking or extreme caution.
IF (and it is a big IF) it is found that fuel slush is the problem then new certification rules will need to be established and ALL plane/engine combinations will need to be checked.
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