It has not happened yet, it is not happening now, and there is no plan for it to happen in the future. I believe it has only happened once before successfully and unsuccessfully more than once.  The "world renowned" experts don't appear to have much of  track record to back up your exaltations. In other words, what they have instead mostly is a lot of wishful thinking on the subject. This whale will most likely die in captivity, of old age, and would likely die sooner in the wild if placed there now, no matter how much rehabilitation it is given to live in the wild.