He thinks it's something new that white means "an ethnic group that has made it," and in fact goes on to bemoan how "this new division is as likely as the old to create nasty, corrosive, sometimes fatal battles over which racial groups get the spoils."

I'm annoyed that he seemingly doesn't get that for centuries white always meant "an ethnic group that has made it." Despite his allusion to the title of a work showing exactly that, he obviously didn't pick up on the point.

I don't think he's ignorant of the history of the term - he is pointing out the ambiguity of it and the confusion it can cause.