Because it is up to each individual how much of their personal medical information is released.
They have, for example, said about the king that his enlarged prostate is common in men his age and is benign, but it does need treatment. The King is said to be keen to share the information about his diagnosis to encourage men who may be experiencing symptoms to be get checked.
It's up to the PoWess to decide what (if anything) to put in to the public domain, and also when. Answer is, nothing right now