If you've read the script for the interview with M&T on the CC web site you'd know a few things.
First, is that they've gotten a lot of criticism over SP by the TV Critics. One of them claimed it was "wall to wall fart jokes", and their opinion was, you think *THAT*'s wall to wall fart jokes, wait till you see *THIS*.
So in a way, this was really a big old Fuck you to the critics, as well as a good joke to play on the fans. Something else is that they're tryint to drive home that "Canadians all look alike" and then try to make you notice that there's one other southpark regular character that looks an awful lot like T&P.
Second is that they plan to leave no stone unturned in their quest to insult everyone, yes everyone. parents, christians, mulsims, jews, sick people, old people, celebreties, homeless, visitor watchers, whatever.. EVERYONE will be insulted at some time or another.. Just get over it.
Just be glad that if this is the only thing they do that insults you, you're probably pretty damn lucky ;)