Barsel, I am somewhat perplexed by your post at 23:15.
King Charles does seem to want to improve his relationship with Harry, as has been reported often. We will wait and see what happens but I do not believe the King would wish to exclude Megan in his efforts towards a rapprochement with Harry. Following your posts on the Tattoos thread I thought you might have more understanding.
Since Prince Edward married Sophie in 1999, it was understood by the late Queen, Prince Philip and Prince Charles that in full time the Earl of Wessex would become the Duke of Edinburgh. However, it would be the decision of the title holder (Prince Charles at the time of his father's death). The King has made it clear that the number of working royals in the Royal Family would be reduced. He decided to bestow the title on his younger brother. This was done on the Prince's birthday, in March 2023. It is usual for such bestowals to be arranged at times of marriage or birthdays.
The King retains the title of the Duke of Rothesay, which is senior to the Duke of Edinburgh.
As Andrew no longer has any royal duties I see no reason why he should reside in a large residence.