Following the family traditions, these are the titles George, Charlotte, and Louis will receive when Prince William becomes king, but there are some details that could prevent the children of the future monarch from ascending the title even though their father does it.
In the particular case of George, it is most likely that when his father ascends to the throne, he will grant him his current title of Prince of Wales without any problem, just as King Charles III did when he became sovereign after the death of Queen Elizabeth II.
The title of Princess Royal is carried by the eldest daughter of the monarch and is held for life. That means that even if William comes to the throne, his eldest daughter, Charlotte, will not get the title because Princess Anne is still alive and will hold the position until her death.
For the youngest son, the royal title would be Duke of York; however, like Princess Charlotte, Louis will not be able to take the position as soon as his father becomes king, as it is a lifetime title currently held by Prince Andrew. For that reason, Harry, even being the second son of the current monarch, was not granted that title.
