I agree the word "wrong" is questionable. However, I do believe, especially for someone who has had their world rocked by a serious, worrisome diagnoses and just received their first treatment, there are more thoughtful, sensitive times for a visit than another. Usually, we would offer to visit but also be prepared to postpone that if the one we plan to visit isn't up to it. We know the King spoke with Harry prior to the world release but have no idea what was said, and rightly so. The King is no doubt in shock and after all these years of waiting for his turn as monarch and with so many plans and ideas he wants to implement shelved for the time being, this is a dreadful time for him no matter what positive spin is put on it.
From all I read, the King wants to heal the situation with Prince Harry and still describes him as "my precious boy" , but there is a tremendous amount of hurt, not just personal, but regarding Harry's words and behaviour towards Charles's father, mother, wife, other son and daughter-in-law.