Oxman didn’t resign
She's pretty much self-employed and out of academia, so that probably wasn't in the cards to begin with. Perhaps her company will lose some business, but I kind of doubt it. The stuff she does seems sufficiently low-profile that nobody will care that she plagiarized a bit.
I mean, if you see a bit of sculpture in a corporate lobby, you're probably not going to wonder if the designer stole a paragraph in a thesis, let alone care.
What's racist? Seems to be entirely based on Cheong's decade-plus of well-documented online behavior, not on his race.