A - Thanks for the question. No it is not true. The Catholic Church upholds that organ donation is a good thing, in most cases. Thus, the Catechism of the Catholic Church says.
John Paul II said:
The Gospel of life is to be celebrated above all in daily living, which should be filled with self-giving love for others....Over and above such outstanding moments, there is an everyday heroism, made up of gestures of sharing, big or small, which build up an authentic culture of life. A particularly praiseworthy example of such gestures is the donation of organs, performed in an ethically acceptable manner, with a view to offering a chance of health and even of life itself to the sick who sometimes have no other hope - Evangelium Vitae, 86.Thus, as long as organ donations conform to the moral law and don't infringe upon the health or life of another person, they can be morally licit and even acts of charity. So, someone could still be canonized if they were an organ donor.