Craig Wright has been claiming for a number of years now that he is Satoshi, however given multiple chances to prove it with a simple message signing that he has never done so or at a minimum always has a reason not to.
It is true that the message is validated that you reference and checks out. Whats does it prove? Not much other than most likely the holder of that private key is NOT Craig Wright, unless he is truly a self deprecating individual. Which I don't believe to be the case because his ego would get in the way.
@interia - Great to see you over here on Peakd, I miss the old discussions we used to have back on Discord.
I wonder if he's trying to conflate elliptic curve message signing with legacy, hand-written signing? It's a weak strategy but it will work on weak minds.