this was already discussed a million times (use search). Satoshi's account here is locked and besides posting on that account does NOT prove anything as bitcointalk database is not the safest thing in the world compared to a digital signature from a bitcoin private key!
Yes the forum account wouldn't change anything unless Theymos confirm it .
And it is the best way to prove show us that he could use or have an access to Satoshi's BTC wallet.
But of course we already know that it would be impossible since it has been said so many times and have been proven that Craig is a fraud and he couldn't really give out a clear proof that he is indeed the real creator.