Harry won't be going to Balmoral. He's going to the Well Child Awards and thinks he can meet with his father while Charles is in London for his weekly cancer treatments.

And the cousins will not be available to meet Harry's kids, even if he brought them to London. They will be in school. And even if they weren't in school, can't see William or anybody else, other than Eugenie, wanting to meet up with Harry to facilitate a meeting between their respective offspring.

Once again, Harry will arrive with a list of demands because he still sees himself as the injured party, and the only concession he's willing to make is inform his family of his upcoming engagements so that they can schedule around him.

Charles is an idiot if he meets him. Harry has no control over the actions of his wife, and she will continue her smear campaign. And any agreement Charles reaches with Harry without William being on board will be null and void when Charles dies.