I don't doubt that the situation as reported exists.
I'm not convinced that it was intentional, or that it's a bad thing.
It could happen by entirely innocent, and defensible, means.
Did you ever notice that just when you think you know where everything you buy is located in your favorite store, they move some of it, for no apparent reason? There is a reason.
My friend Peter ran several 'contract departments' in a fair number of suburban department stores, and gave me a glimpse behind the facade. Peter knew how to arrange items and shelves for maximum profit, because he moved items around regularly, and kept track of how well each item sold at each location. That was thirty years ago, and Peter did all that tracking by hand.
You can bet that Wal-Mart has computers tracking sales rates, in real time, per item, per store, by location within the store, so they know the ideal location of every item they sell, in every individual store, to a resolution of inches or less. All they have to do is adjust the shelf location of everything so as to maximize each store's profit.
Clearly they know how to do that.
In fact, they are obligated to do that, on behalf of the shareholders.