the good place has a morality system which is based on impact, not intent. by citing pewdiepie, the show isn't commenting on if he's "actually" racist or not; the show is pointing out that his actions put more harm into the world than good. regardless of his "true intentions," by paying someone to hold a "death to all Jews" sign and promoting channels that support white supremacy, he has done more harm than good.
and before anyone complains about how "he raised money for charities" or whatever, that doesn't negate the harm he's done elsewhere (especially given the whole fiasco with his recent "attempt" to donate to adl. regardless of your opinion on whether it was right or wrong to cancel the donation, there's no denying that white supremacists felt, once again, emboldened by his actions).
this "impact vs. intent" morality actually goes pretty well with the claims his fans make that these acts are satire. anyone who studies literature could tell you that true satire, effective satire, mocks oppressors/the powerful by mimicking them to such an absurd degree that no one can mistake what they say for agreement. people generally cite jonathan swift's "a modest proposal" for a reason — he calls attention to starvation in ireland by suggesting they eat babies. it's absurd and appalling, exposing how poorly the english treated the irish.
this is why pewdiepie's actions are not satire. he doesn't seem to be mocking antisemites; he's simply behaving the same way. that's not satire. that's just being a white supremacist. paying people to hold a sign and promoting a channel are not big, ridiculous actions that obviously point to satire. using the n-word when you're mad at a game is not satire. those aren't big, ridiculous actions that clearly mock those who hold those views.
that's just supporting those views, plain and simple.
and that's the point the good place is making. even if his fans are correct and he's being satirical, he's still harming people. he's still exposing people to antisemitism, using the n-word, and exposing kids to channels that promote white supremacy. he's creating a place for white supremacists to find each other and feel emboldened to share their views with children.
so that's what this means. he has put a lot of bad into the world, and no defense of "it's a joke!" negates that.