This is about the titles of the children of the Duke and Duchess of Sussex.
Per the 1917 Letters Patent as great grandchildren of the sovereign they were not entitled to any titles at the time of thier birth.
Now that they're grandchildren of the sovereign in the male line they are entitled to be Prince and Princess of the United Kingdom.
Their parents may not want them to use their titles and the King may issue new Letters Patent removing thier titles but it does seem they at least do have these titles in theory if not in practice like the Wessex children.
Now some are arguing that when Queen Elizabeth II issued new Letters Patent extending the right to have titles for all of the future children of William and Catherine, instead of just George who was the only child to be entitled to a title under the 1917 Letters Patent, but did not extend that right to the future children of the Duke and Duchess of Sussex; she there by voided, or made obsolete, the 1917 Letters Patent that had granted the right to titles to the grandchildren of the sovereign in the male line.
I thought it was clear that when Charles became King the children of the Duke of Sussex would be come Prince and Princess of the United Kingdom....now whether the Duke and Duchess of Sussex want them to use the titles or that the King may later remove them is another matter.