Only tangentially related (but hey, it's HN) - I'm so happy about the support/requirements for trailing commas in the modern language syntax:

    x = [
      123,
      456,
      789,
    ];

It makes editing such a list so much easier. Also, the commit diffs are cleaner (you don't need to add comma to the last element when appending a new one).

  x: [
    123
    456
    789
  ]

"I'd like to thank my mother, Ayn Rand, and God" is the usual example.

Yes, you can reorder the list to remove the ambiguity, but sometimes the order of the list matters. The serial comma should be used when necessary to remove ambiguity, and not used when it introduces ambiguity. Rewrite the sentence when necessary. Worth noting that this is the Oxford University Press's own style rule!

Wikipedia has an interesting example where it's still ambiguous:

  They went to Oregon with Betty, a maid, and a cook.

It's not clear whether Betty is the maid. But tbh removing the comma doesn't help either.

Personally if I wanted to indicate that Betty was the maid I would put "a maid" between brackets or hyphens.

    They went to Oregon with Betty [a maid], and a cook.

You'd only use the Oxford comma when the list is 3 or more items.

.. and in your example, unnecessary.

Or maybe I missed the joke.