First, I commend you for living a life of integrity. Double that when you have a disability and sacrifice your preferences for the unselfish standard of chosing to do what is morally correct. You and I are starting at a mirror point as we discuss issues.
My first issue with the organizations requirement for personal and medical information disclosure in order to receive freely available related medical information they discussion in is that it is an unreasonable demand, imo, which is exclusionary to some of the very people the non-profit disease- supporting org exists to 'help.'
There may be many reasons why they want to accumulate medical + personal data. Financial gain may only be one reason.
The real harm of this is how seriously this places a person/patient at risk. As you mentioned, data breaches happen more often than we even know. Beyond privacy risk, there are safety and security risks. Let's say data is breached by hackers looking for wealthy disabled and perhaps dying people. Literally, targeted victimization is fully enabled by the detailed information required by this organization, should this fall into malicious hands. Also, what if you didn't inform certain people of your medical problems and something comes in the mail to your required listed home address or substituted your workplace? Since we've learned here HIPAA does not apply here, what would prevent that if bad judgement was exercised? And the idea that it wasn't disclosed that the incentive with prize possibility to have your conference badge scanned by as many vendors as possible may be a process by which you are transmitting your personal data. Vendors are not even ethically bound to protect your interest or privacy if you directly + voluntarily share information with them. Who knows where all that information will end up.
However, I did have a subsequent experience recently subsequent to submitting that extensive information then rescinding it. I received a non-bulk letter that provided information about various avenues available to me to get reimbursement for pre-death expenses and funeral costs. This was not an insurance policy solicitation. It wasn't a reverse mortgage mailer. This was custom geared to me. It included govt options and other non govt resources. This was not a govt mailer either. There was no return address. I never received any like it before. Needless to say, it showed me the tip of an iceberg I'm likely now in the waters around. I immediately flashed on the option I originally checked for "treatment" from the mandatory pull down menu indicating "none" and wondered if this resulted in the generation of this letter, which had my legal name on it. Bottom line: we live in an information and digital age that has exalted itself over people, imo. I am becoming aware of many realities these days that I probably should have learned about years ago. I feel like I've been buried under an avalanche of harsh reality. Digging out ......slowly