In this case I think they are totally justified in their decision. Why? Because the anti rejection drugs lowers the immune system making a person much more vulnerable for Covid-19 infection. If a Covid-19 infection doesn't kill the man, it can leave permanent organ damage. Most younger persons who die form Covid-19, die from "sudden organ failure". It is more productive to give the heart to a person who takes better care of theri health and has a better health outlook. That is even before considering how as a patient he would put other patients at risk of infection as well.