To me plastic surgery goes into the same category as tattoos, piercings or any other body mod. It's the sole business of the person getting it. Is tattooing "Mr. Cool ice" all over ones body ill-advised? Not my body, not my say.
The reason I'm kind of passionate about this is because I saw first-hand why the non-famous get plastic surgery. I had a good friend who really suffered under her "witches nose". The reason it got to the point where she got a rhino despite not really having the money for it was an accumulation of societal pressure shaming her for her skin color and families wealth. She felt that she couldn't get a husband (a must have for every woman where I grew up) because she looked too much like a stereotypical farm girl (she wasn't a farm girl, but "looking like one" was bad enough for her) and indeed married very late. Whether that was a self-fulfilling prophecy or not doesn't really matter I believe, the psychological damage she suffered at the hand of an oppressive patriarchal society that shames women for how they look and then shames them even more when they get plastic surgery was severe. Maybe she lacked strength of character or role models, she at the least lacked the wealth to carve out her own path, but these "haha woman even uglier after trying to be prettier" kinds of "jokes" do harm.
For another example look at how this poor woman suffered for an ad she appeared in: https://www.bbc.com/news/world-asia-34568674 . And I'm sure you can guess how much shit the "husband" in the ad got.
I would look at why these people put their bodies in harms way, at why their body dysmorphia is so severe that they would do such self harm. Where is their "obsession with what a woman should look like" coming from? Shaming people for how they feel has never worked, the fight must be with the patriarchy and not those trying to survive under it.
To be clear, this is not about Kristi Noel, I dont care for her. My problem is with south park playing a very cheap trope that they played before on Sara Jessica Parker, on Michael Jackson (a racist component has appeared) and on trans people as a whole (the "Mr. Garrison's Fancy New Vagina" episode).
There is a discussion to be had about public figures like Ms. Noel, Sara Jessica Parker, Donatella Versace or countless other models, actresses and so on reinforcing patriarchal beauty norms through their plastic surgery because they have been presented as role models (and later, objects of ridicule), but this is south park we are talking about. Their "satire" isn't that deep.