If you classify "Han" like "black people", "Hispanics" "Asian/Pacific Islander", or "white people" I would agree that there are "Han Chinese".
I don't think its a very useful classification, but I do not think its stictly scientific, its more cultural since ethnicity is a social heuristic, classifying races isn't scientific but its has uses. If we classify it as a group of Y-haplotypes it can have a scientific basis, but its still classified by social norms. https://www.semanticscholar.org/paper/Y-chromosome-haplotype...
I don't think its a very useful classification, but I do not think its stictly scientific, its more cultural since ethnicity is a social heuristic, classifying races isn't scientific but its has uses. If we classify it as a group of Y-haplotypes it can have a scientific basis, but its still classified by social norms. https://www.semanticscholar.org/paper/Y-chromosome-haplotype...