I was looking for a bag of nutrageous bars a few weeks ago and have checked every single time I've been back to the store since then. I remember buying a bag of these maybe 6mo-1 year ago; it doesn't make sense that they've stopped selling them.
Walmart seems to trial run a lot of products. I think they only do it when the vendor gives them a good deal. If they become popular and the vendor wants full price, they drop them. I say this because a few products I loved disappeared from their shelves shortly after I discovered them.