They aren’t complaining that he had a black son, but that he’s an “undercover Democrat” because he’s stated that he learned about racism from the kid, saying things like, “Michael being a Black American, and Jack being white Caucasian. They have different challenges,” he said. “My son Jack has an easier path. He just does.”
Further, there was a question as to if the kid was real since there are no photos. That led to the new clarification:
Speculation about whether Michael was a real person prompted Johnson’s office to clarify. “When Speaker Johnson first ran for Congress in 2016, he and his wife, Kelly, spoke to their son Michael—who they took in as newlyweds when Michael was 14 years old,” said Corinne Day, Johnson’s communications director, in a statement first reported by Newsweek. “At the time of the Speaker’s election to Congress, Michael was an adult with a family of his own. He asked not to be involved in their new public life.” Day added that Johnson “maintains a close relationship with Michael to this day.”
So if we are to believe him, there are no photos because that is the way the now-adult kid wants it.