>The biggest dangerous part of removing a kidney isn’t the act of removal, it’s the long term lack of having it.
So? You wouldn't mandate mandatory kidney removals if we could mitigate the long term risk of not having one because that risk isn't the reason we don't unilaterally harvest organs from people against their will.
Regardless of where the risk is clustered (at the event or in the long tail following it), it is the harm to an individual via a non-consensually driven medical event.
That being said, I think it is perhaps noteworthy to say if women lose the bodily autonomy for carrying children, it is outrageous that dead people should retain the bodily autonomy to not be organ donors.