The words orgins are reported to come from Jamaica. It means exactly what I have been stating it to mean. The mother of a child usually one that is unmarried. The word has nothing to do with race. It just doesn't. Was the guy who put it up doing it for racial reasons? I have no idea. I'd be speculating. He may of said, "Man, Baby Mama is a funny term, lets use it." Or, "We need to try target a younger demographic." Or, "I guarantee I sleep with her tonight, if not, I'll put Baby Mama on the screen."
But like I've said this whole time, Baby Mama is a word that has no racial back round. It is used for whites, blacks, and I'm sure J-Lo, whatever the fuck she is. The fact that people try to make it an issue is why race continues to be a problem. If we can't all use the same language how in the heck can we share the same land?