I think the episode only took shots at those who flock to fluids from icons calling them miraculous. Beyond that, I didn’t catch that it was any more anti-Catholic that their parody of OBL in his cave or jihadists shooting down Santa was anti-Islam.
It’s South Park. They parody the fringe in everything.
Well, that's the first time I have ever heard anyone refer to the Mother of God as "fringe".