The ad is interesting because of the stereotypes used and very interesting wording choices. The commercial states competitor's beef for hamburgers come from "Nooneknöwswhere." Nooneknöwswhere is shown as a tundra=land in winter with people who speaks with Eastern European accents. The cold, wintery land plays on Wendy's mocking of other fast food chains for using frozen beef.
The Eastern European-Scandinavian mixed stereotype-land allows for a non-controversial place of origin myth. If Wendy's were to play on the "McDonald's uses Latin America"-myth then the commercial could backfire and be cast as racist.
In reality much of American McDonald's (and Burger King's) beef comes from the United States. A very small minority of it is being imported from Australia and New Zealand. It would be hard, but not impossible, to make a funny ad mocking the use of Australian and Kiwi beef. However, people are unlikely to have any fear of Kiwi and Australian cow in their hamburgers unlike some mysterious Eastern European beef.
The advertisement takes an unintentional humorous turn with a statement that Wendy's uses only "North American beef." This means Wendy's beef can come from anywhere between Canada and Panama. This accidentally puts Wendy's at risk to the Latin American-beef myth. In the past Wendy's has refused to discuss its supplies due to "competitive reasons."