Harry and Meghan will be treated by the Royal Family as they were at the Platinum Jubilee and at the Queen's State Funeral, only 10 times worse than at the State Funeral. The public booed and turned their backs on them at the Jubilee and would have done the same, but didn't out of extreme respect for the late Queen at her Funeral.
At the Coronation, there will be no limit for the public, it wouldn't surprise me at an increase in booing, catcalling, turning their backs. Then the reception they'll get at Westminster Abbey. It was terrible at the Jubilee Service of Thanksgiving, it'll be worse at the Abbey.