Comma with OR in a verb list containing in an introductory phrase

Question

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.

Answer 1

The New York Times stylebook
"In general, do not use a comma before and or or in a series."

(quoted in wikipedia)

It is not the case that American English always uses an Oxford comma, though it is more common in America. In particular the NY Times does not.