Making fun of any religion is fine. No religion is above reproach, no religion is beyond mockery. None of them.
>Making fun of marginalized religions
Here's a newspeak term. There is no such thing as a "marginalized religion". This is a fictitious concept.
>which are already frequently ridiculed because they're different from what the dominant culture does, and which are under threat, either overall or within a given area, is a very different matter.
Good, every religion should be ridiculed. There's no culture that's beyond ridicule.
You're trying to create an illogical concept where hatred of White people is a reasonable thing. You can't come straight out and say it, so you launder the idea through a luxury belief and magically the hatred is tolerable.
>The problem with cultural appropriation is specifically that it exacerbates marginalization and discrimination against already-marginalized groups.
No it doesn't, because "cultural appropriation" doesn't exist. Upholding cultures even if they're backwards because it's politically fruitful breeds resentment. This is "baizou" behavior.