They are already overcharging compared to shelf prices, that is the very thing they’re introducing this to prevent in order to avoid bad publicity and legal costs in states where it is mandated that they should show the same price.

Also, the Walmart employee being yelled at isn’t an issue for them morally, but making people mad and also holding up lines is really not something to be desired. How much do you think they’d earn from this kind of surge pricing before they get flooded in lawsuits?