Why on earth should it be in the public domain? Apart from commercial confidentiality and IP issues, the travelling public are (in the most part) not metallurgists or aeronautical engineers, so the information would largely be meaningless. The people that need to know, do now know - the regulators and other OEMs.
I was around when the 76 A slung a couple of rotor blades and know how heartbroken some folks were that they failed to get it right despite their every no holds bar effort.
I was told, on my 76 conversion, that the speed with which Sikorsky introduced the fix indicated that they already knew about the issue, and had been working on it. Without telling the operators. This was why Alan Bristow cancelled (most of) his 35 aircraft order. That might be apocryphal, but the source was around at the time.