As long as the ferrets don't key in on the words transgender female in my medical records, 'cause its there in every entry from 10 years ago, we'll be safe enough.
But if they start mining for medical records that say "trans..." anywhere as well as keying on HRT, then all bets are off. Those of us that have officially changed name or gender are potentially at risk only where historical records can be tied to current ones. We need the law to protect us!