Coincidence.
Im not a conspiracy theorist; therefore I do believe this is more coincidental than anything.
For every couponer, there are many more who pay full retail price. For a retailer to pull items, just so they dont lose the pennies on coupons/ad matches, etc. just would not pay. Consider even at minimum wage how much they are paying to have one or more employee pull stock, just to not allow some customers to use a coupon and price match items.
If they did, their stores would be empty on many items, and they would not sell a whole lot.