There is substantial variation in those samples themselves let alone between those samples and the bitcoin whitepaper. Some of them are written like bad text messages and some are perfect but awkwardly formal, and some are perfectly conversational. If those posts were consistent and at odds with his bitcoin writing (on the forums -- including the whitepaper is silly, virtually everyone writes differently for 'formal' papers) maybe they'd be decent proof, but they are all over the map.

Also, how about adding this link to this list:

https://www.national-preservation.com/threads/preserved-bars...

Another Dorian post on trains which is in a lot of ways remarkably similar to the bitcoin guy's writing.