It's authentic, but isn't new TFW2005... as it was revealed 8 years ago at BotCon 2005. Apparently one side of that is in the Vault book, while both halves and the story behind the lunch that created it, was shown off at BotCon 2005. I guess for many of today's fans, something from 8 years ago is "new".
I just had a look at my BotCon archives, and I actually have photos of both sides as well, as it was on public display at the Hasbro Exhibit, so shouldn't be news on TFW2005.
I think the reason it is being posted up though as "news", is that it is being confirmed that Aaron Archer has indeed left Hasbro (a rumour was going around last week), and re-posting about the napkin is just a way to make it public... so I might might modify this topic to reflect it.