“Hello 911 whats your emergency?”
“I am having a heart attack”
“Your number is registered to James A Smith is that you?”
“Yes, please hurry”
“Sir, your registered as being against being put on life support. But you are an organ donor, so I have canceled the emergency ambulance but they will be along soon to collect your organs. Good day sir.”
That is precisely what will happen, a guy will roll up with sirens blaring and jump out with a bloody apron and a set of knives.
Back when the Monty Python troupe filmed "The Meaning of Life", they included "Part V - Live Organ Transplants".
I'd say the U.K. is just a few steps removed from seeing that actually occur. It looks as though they'll first see the scene from Grail where the fellow (equivalent of today's Paramedics) "assists" the old fellow in "getting on the cart".
Guys, those were *comedies*, not blueprints for social planning.