So he leaves the bitcoin community in 2010 and risks to check in a conspiracy theory forum in 2013 just to say he's real? LOL!
Even more, "his" writing style looks different in 2013.
And that signature may or may not mean anything, but as it is, it's just a signature out of context. Can be anything.
Nice try, but wrong audience.

Exactly! Why would he post that in other forums if he is real? I am not seeing any valid reason why he will do that, if he is indeed Satoshi. A lot of people just want to mess up people's minds. They can easily create such seemingly signed message but it doesn't say anything at all.