Damn SJW's always trying to ruin everyone's fun.
The language barrier definitely adds to what makes it funny so you can't just replace it with a North American person (whether that person is black, white, hispanic, Asian), then it wouldn't even make sense it would just be weird.
You could replace him with a guy of any race from another country though. My name is Pierre and I am FREEEENCH! Laughing at that would that be racist? I don't think it would be. But then again I might not be as politically correct as you or others.
Weird antics like dancing and goofing around in the dugout also get a lot of play, whether the player is Japanese, Hispanic or white.