Though I am firmly in the camp that the Oxford comma should pretty much be mandatory no matter what, and I will shank a bitch if they say otherwise.
To be fair, what you have there is not an "Oxford comma".
An Oxford comma is used to separate the penultimate item in a list, from the last item.
The list must contain at least 3 items.
"I need you to get me a knife, some butter, and the bread."
Purists will argue that there is no need for the final comma. It's made redundant by use of "and" as a conjoiner.
You cannot conjoin with a pause.
Having something which separates followed by something which conjoins, seems rather counter-productive.
We want to separate them, then bring them together?
As a matter of efficiency, why not just bring them together? lol
"a knife, some butter and the bread."