south park is a product of the 1990's! its origins lean heavily on the still-true left/democratic party's pro-censorship leanings
just because the recent right/republicans were able to more effectively lean into the meme-heavy southpark-type (crude, male-targeted) humor as marketing doesn't really track with your last assertion (for me)
The US-Left is pro-censorship? My recent memory of headlines was the US-Right attempting to ban books. What am I missing?