I think this is one of those cases where the teaching never changed but everyone forgot it. I still hold to the “no Sunday shopping except in case of necessities” because it just makes sense. If we shop on Sunday unnecessarily, we encourage stores to be open, etc.
It’s actually not that big of a deal to me. No Sunday shopping–my catechist taught it and the rule still holds. If people have forgotten, they just need to be reminded.
From CCC 2187: “Sanctifying Sundays and holy days requires a common effort. Every Christian should avoid making unnecessary demands on others that would hinder them from observing the Lord’s Day.” If we didn’t shop on Sundays, more people would have Sundays off, because there would be less business. The argument that everybody shops on Sunday has no weight. If we want to follow the 10 commandments, we should do our best to follow them, even if we see no examples from anybody we know.