From Wikipedia: "Without a serial comma, the above dedication would read... a phrase ambiguous only if the reader accepts the interpretation..."

In this case the serial comma isn't creating any ambiguity, the bad writing is (and the serial comma shifts the ambiguity to the second/third item being listed). When they suggest a better way to write the example sentence, it uses the Oxford comma both times (though I'd argue that the second sentence isn't a solution).

I agree that nothing is ever absolute (hah), but the Oxford comma takes care of ambiguities most of the time, and merely shifts the ambiguity around when appositive phrases are thrown into the mix. And reducing ambiguity should be the goal of every writer.