The relationship it has to the Olympics is to serve the many thousands of overseas tourists, who come from civilised societies where you can go to a shop after 5pm on a Sunday. I'm a hotelier, and honestly tourists cannot believe it when they're told our Sunday trading hours.
I don't really get why a shop worker would or should be paid more for working Sunday than any other day either. Plenty of jobs require weekend working whih forms the standard working hours of the job. Different for overtime or nights working but weekends should be standard in service industries.
And I hope it does lead to relaxed Sunday trading laws. It's so archaic to treat Sunday as some sacred day, because of religious bullshit.