I'd say most interviewers aren't aware that Fantastic Beasts takes place in the 1920's. Since Harry isn't born until 1980, it would be rather impossible for him to be in it. Granted, they could begin the movie in the present time with Harry making an appearance and then go back to the 1920's, but the only character I think this would make sense with is Luna Lovegood. She is, after all, the one who married Newt Scamander's grandson. (Or great grandson. I forgot which one.)