He was acknowledging that their origins were African. Which they were. The humorist that you are talking about is Trevor Noah and he is from South Africa. He is an immigrant. So it's not really a US thing. Its a being subjected to a double standard thing. In the US when you're a minority and you are doing something positive you are considered without doubt an American. But when its something negative or objectionable to some people race comes in to play really quickly.
When I was growing up it was common for the news to report the race of a subject when it was a black person doing the crime. But you knew the person was white when race was not mentioned at all. In the past few years that has gotten better but it was definitely a thing in the not too distant past.
When a large segment of the population thinks its okay for police to profile based on race its hard for people subjected to it to not think about race in all avenues of life. Because its something that you deal with on a regular basis.