I'll admit to a LOL here, but overall I didn't think this post was arrogant. This is an established mathematician reviewing the work of a another with the benefit of hindsight. Sure, he draws parallels to his own work but that's because from his perspective that's how things have evolved. I imagine an equally qualified person with different specialities might see connections to their work too.
Wolfram's New Kind of Science may wind up archived in the manner of Leibnitz's notes, and intellect of the 24th century may think they have it right up until Wolfram throws "souls" into the mix. But surely one among them will admire his earnest yet flawed attempts at a practical calculating machine - or perhaps not, as bits and bytes do not display well in a case.
Wolfram knows himself, and recognizes his own mortality. If he sees some Leibnitz in himself, that is by contrast to Newton.