We will recieve Bitcoin Gold at november, not earlier. It seems, that you have made good trades overnight. 
This is the only valid explanation for this or maybe he has forgotten about it but the fund must surely come from somewhere. My advise, don't spend it yet until you know the origin. Also, I don't expect that Kraken would do that sort credit and wont even do the announcement themselves. Even if they did credit you, I don't also expect that they would credit the equivalennt in fiat rather in the coin and wait for you to decide what you want to do with it.
