I think it’s a good thing to close supermarkets on the day of the funeral, plenty of other opportunities to shop, at any other time, people cope with other closures during the year, Xmas day, Easter Sunday, people know in advance to get organised. I am sure many of the staff would like to watch the service and those who don’t can spend the time how they wish too.
I expect the same will happen for the coronation, but that will be a while off yet, no way will another unplanned bank hol happen again this year, I wouldn’t have thought, too much impact on the economy.