Thank you @Abby1 . The "Yellow Sweet" offer is supposed to be a variation on the classic, walmart's description "Try French's Classic Yellow Mustard with a Sweet twist!"
http://www.walmart.ca/en/ip/frenchs-sweet-yellow-mustard-400ml/6000191596969
Your Walmart link as well as the sweet one show that it isn't available instore. "Sorry, this item is currently not available in stores."
So far I haven't found either anywhere.