I use this book in my pre-school classroom in conjunction with The 3 Little Pigs to talk about anti-stereotyping. There are good pigs and bad pigs, and good wolves and bad wolves, as there are good people and bad people! The moral here is to choose friends that are good and respectful to you and not based on what they look like or their background.
The other thing i like about this version is that the pig was bad, but he changed! People that are bad, or do bad things can change, and when they do we should be willing to accept their friendship!