In what way are they “clearly very happy”? They’ve said nothing about it? That’s not proof, its not even refined speculation, it is what is, that being nothing.
Governements don’t comment on lots of things, that doesn’t make them true, no matter how hard you want it to be.
As for the writer, well I know he has written a book where he makes these claims, he will sell that book for money. He could make money from any number of versions of events but seeing as these are the ones in his book, I would reasonably assume he has a vested interest in the way he tells it.
Confirmed is a fairly binary adjective, it is either confirmed or not, where is the confirmation?
I can see you are desperate for this to be true, it clearly dovetails beautifully with your belief system. It probably is, but I’m merely pointing out that nothing has been confirmed, there is no proof and that the guy making these claims has something to gain from them.