Entitled
As the grandkid of the future monarch, Archie will now have the title of “Prince” if he wants. Harry is probably not going to have a new title when his father accedes to the throne. Of course, it is definitely very possible that he will be granted a new dukedom by Charles, but it is also likely that Harry and Meghan will simply remain the Duke and Duchess of Sussex. If at this point you are still not confused enough, there is more.
Holding Titles
William is now called the Earl of Strathearn and Baron Carrickfergus, but he will have to assume new responsibilities when Charles becomes the king. As a consequence, William’s titles will have to change. Once Charles becomes king, William will become the heir apparent to the British throne and the Duke of Cornwall. Actually, the duke has already started to attend duchy meetings. On top of that, William and Kate are expected to be given the titles of Prince and Princess of Wales. Charlie Proctor of Royal Central said in November 2018 that plans are underway for the transition.