Scare quotes?
I guess I could have used italics but they seem so snarky sometimes.
eta: Here's what's wrong with the Oxford comma. It's grammatical kludge. It is the unnecessary feature that keeps intruding on you in Word that you need to go spelunking through nineteen drop-downs to STOP. It is inelegant. It is frequently not necessary. It is as stodgy and dodering and slow as an Oxford Don.
It is a matter of style, not usage. When I want to clarify the list I am writing I will use an extra comma as it is needed. Otherwise, it slows the rhythm of the sentence. It creates an unnecessary visual impediment.
Ultimately it is a matter of the writer's choice, not the editor's. It is not required in all instances.