Yes, not a coincidence.
Why are they only finding this now?
Surely it doesn't take all that time to covered deleted data?
No indeed they (FBI, Malaysian government and airliner) already knew this information for a long time but they kept it secret.
We the public only hear about it now because some american newspaper got their hands on classified FBI documents through a non disclosed contact.
The reason is probably that it is as the link below states it, circumstantial evidence at most, it is not hard proof that this is the root cause.
Now with hundreds of grieving families do you want to tell them this without 100% being sure this is what happened
Perhaps what also was in the consideration of the airliner was the risk of getting millions in claims, just as German Wings is now experiencing.
The reason that this non disclosed contact now at this moment in time releases this document is ofcourse pure speculation, I myself can think that if I had this knowledge and knowing that the search came to an end and we never would find out the real cause due to unable of finding the wreckage, and the relatives would never know this part of the story (perhaps the truth) that would very well be a damn good reason to personnaly leak that document to the press.
Another more commercial reason could be that this will vent of the suspicion that there was something wrong with this new plane, I mean it was pretty new and any crash is bad commercial news for such a product. If you know how much one such airplane costs and that airliners base their buying on how reliable the planes are, this could well have been also a reason to release the document.
http://edition.cnn.com/2016/07/22/asia/mh370-pilot-simulation/