Your advance directive regarding your organs overrides anything your family might wish.
Please don't drop off the list. The organ recipients I know (many, many people - some recipients of as many as 5 transplants) would die without a transplant. I also know many people who have died while waiting for a transplant.
For some organs, there are alternatives (at least in the short term). Kidneys, for example, can limp along with dialysis for a while. Others can receive a transplant from a live donor (kidneys, and liver, for example).
Many family members of those who need an organ are organ donors, including live donors. My daughter will need a liver at some point in time. Since it is currently in the news - she has the same disease Jamie Redford (Robert Redford's son) had. He had two transplants. Because she won't need a transplant before I age out of donating (which I now have), I was evaluated to donate part of my liver to another person with the same disease. At the time, I had no idea what his politics were - but I knew that without a liver he would die. At the annual conference for this disease last year, one person with the disease was wearing a T-shirt with a QR code - looking for anyone interested in being a live donor. The mom of a newly diagnosed teen saw the shirt - and agreed to be the donor. It was announced the first day of the conference this year (last Friday) that the transplant took place 16 days earlier. The donor had healed enough to attend; the recipient was not well enough yet and attended by phone. I have no idea what either of their politics are. I know many parents, siblings, friends, and spouses who have donated part of their liver to their loved one - and others who have done so for complete strangers. The least you can do is to share your organs when you no longer need them, rather than burying them in the ground to rot.
Rather than looking at it as potentially keeping a magat alive, the withdrawal of your donor consent might be the reason my daughter dies.