I would guess the issue is royal protocol would have been written many many years ago. Where news was slow and people where attached more to the Royals. So things stopped as a mark of respect as the news swept the country.
So kinda outdated now aways.
Interesting article on what goes on if she has passed. Like news reader in black suite and tie and change of bbc 1 programs
both that have happened
https://www.theguardian.com/uk-news/2017/mar/16/what-happens-when-queen-elizabeth-dies-london-bridge
I heard, Robins will be on the pitch before the start of the game. In a big green coat with a pair of sunglasses. Simple minds "Don't You" squarks out of the CBS's awful sound system.
Robins raises his arm and walks off never to be seen again
Sky Blue Sam the elephant pack his trunk
And said goodbye to the Coventry building society arena
Off he went with a trumpety trump
Trump trump trump
And he has only gone and nicked Goddens lawnmower the bastard