Thread:Evil Tim/@comment-1504072-20180822163107/@comment-1504072-20180822175946

Well, Konami's MGS1 biography did suggest his American nationality was assumed, which is stronger evidence than the third-party written Handbook.

But anyway, I'm not sure why Kojima would explain away Big Boss's potential Japanese ancestry. I know many people questioned the original backstory in the old days, because they didn't think Solid Snake/Big Boss had any noticeable Asian physical characteristics (assuming he was a third-gen AJA). So maybe Kojima wanted to use the egg donor explanation to deal with this nitpick, and still maintain the Japanese connection in MGS1.

But you're probably correct that Kojima didn't think that far ahead, since retconning Snake into Big Boss's clone would mean that they'd share ancestry.