www.ncbi.nlm.nih.gov/pmc/articles/PMC4964018/
The NHS organ donation registration form asks for gender NOT sex and allows people to select 'other' or 'prefer not to say', so if someone had had their medical records deleted after gender reassignment, potentially some poor recipient would get an organ less likely to last beyond 5 years and more likely to fail after transplant.
Yet another place where biological sex matters and yet we're allowing risks to go unaddressed for the sake of PC madness.