Sure, except I don't think it was done with that much thought or that intention. I doubt they were trying to dissuade anyone from buying Coke or Cadbury's chocolates.
I doubt it was coincidence, or naivety. I wouldn't be surprised to learn that Coca Cola and Kraft/Cadbury's or whoever just bought them up, were paying Tesco to place their products around the banners.
For the raffle, why not a leg of lamb, the traditional Easter meal.