Here is a sentence from the New York Times.
Every time a person runs a Google search, watches a YouTube video or sends a message through Gmail, the company’s data centers full of computers use electricity.
The initial pharse in the sentence has a list of verbs: runs, watches, and sends. And in American English, we often add the oxford comma in a list. So, why the comma is missing before "or?"
NYTimes writes in American English, so there must be an oxford comma.
Any thoughts on it are welcome.