So wait, it's okay for the Sussex title to eventually go out of the RF but not the Edinburgh title? That doesn't make any sense either. Nor do I believe for one moment that Philip and the late Queen intended the Edinburgh title to be limited to a lifetime peerage for Edward. I believe they intended it to be for Edward's line to hold and understood it would eventually, like the Gloucester and Kent Dukedoms, eventually cease to be a Royal title.

As I wrote above, I hope William recreates the title as a hereditary peerage and includes Louise and her descendents in the remainder.