A paper gives you dozens of phrases through which you could fish for the ones that point towards your desired author, if you wanted. It's sort of like how given a list of my inheritable traits and two potential fathers, you could make a list with a few traits that match with either one of them. If the list is long enough (say you have thousands of SNPs to root through), you might even be able to find a few _rare_ traits that match.
[Edit: speaking of which, interesting to see that a past attempt to out Satoshi claimed a combination of textual and other evidence pointed at a particular group of researchers who filed a patent right before bitcoin.org was bought: https://en.bitcoin.it/wiki/Satoshi_Nakamoto]
The poster's suggesting they ran an automated analysis against a bunch of authors, and that it clearly pointed to Nick. Particularly if _still_ it points that way even if restricted to content-neutral phrases (so it effectively picked Nick out of all crypto researchers, not just out of those that talk about timestamp servers etc.), that's more persuasive: programs won't fish (though you could still repeatedly change the algorithm until it gets the result you want). Publishing it would be interesting.
As is, this is interesting but seems preliminary or shallow--doesn't deal with any other text Satoshi or Nick wrote, doesn't deal with code, and doesn't give us full raw data or scripts. I'm not sure Satoshi is Nick Szabo.
Also, the post-dating had occurred by the Oct 17, 2009 Wayback Machine crawl, but the post content didn't visibly change, only the date. I have no idea if it was anything interesting or not.