Although the complete report is still a long way off, investigators did actually announce that it was caused by a fatigue crack. Should this be reopened since it's no longer speculation?

@TomMcW not sure, sincerely. "there is evidence of metal fatigue" youtu.be/JxNS8H63oAc?t=6m1s to me still does not mean that's the (only) cause. It is likely, sure, but why they would say that they'll need 12-18 months of investigations, if the answer would be so easy to find?

@Federico There's always a hundred things included in a final report. Where did the fatigue crack come from? Why did it take of the cowling? What part hit the window? Why did the window fail? Did the pilots respond appropriately? Did the cabin crew respond appropriately? Etc. Etc. But I'd say the root cause of the accident is clearly a separated fan blade due to fatigue cracking. It seems pretty straightforward and I think the question can be answered.

As the investigation unfolds an answer can be edited to include new info.

But if everyone thinks we should wait, that's cool.

@TomMcW I see your point, and if the question gets reopened I won't object. That's also why I started saying "not sure". I listened to the second media briefing and they seem to be more certain of the fatigue crack (I interpreted that sentence in the first briefing as to mean "seems a fatigue crack, but we're not sure it is one").