The focus of this series was the queen upon which head the crown landed so unexpectedly and it is fitting that the last episode is about her confronting the past, but especially the future.
The queen must revise the plan for her funeral since she'll be 80 soon and this makes her think about "retiring", also because Charles wants to marry Camilla and once he's settled and his situation "regular" he could get the crown without sullying it because of his past misdemeanours.
However, the queen is undecided, because she knows she's the last real "royal". Her family is disappointing and the monarchy itself on the way out. A peaceful way out, for lack of need of such aloof symbols, but way out nonetheless.
The queen's choice of music was quite moving and so was the last scene, very well done.
After Elizabeth, Charles will take the crown on his way out, followed by "approachable" William, with his ordinary wife and his family squabbles with his brother who makes everything public. Goodbye aloofness, but also dignity. Enter the social media era, it's not just a queen who dies, is royalty that vanishes.. and I'm not even a monarchist.