This means no sales, no themed merchandise, no decorations. December 25 and most other day are treated just like any other day for all stores malls, restaurants, ect.
You’d still get non religious holiday events like mothers days, or independence days.
What whould change?
I wouldn’t be shocked at protest over Walmart not selling 20foot glitter crusted crucifixes or whatever. But I think most know the difference between defiance of religious values and non-compliance. I’m for up north though so there’s a little less zeal.
Also shooting up a Walmart probably ain’t the best move. Folks there are likley armed to the teeth and itching to shoot back.