I actually regretted donating because of this very reason. If I’d thought about it I wouldn’t have. But the bethematch.org marketing material really tugged at the heartstrings. Never again, though.
If your concern is that your genetic information is no longer entirely private, wouldn't continuing to act as a donor cause no /further/ harm? (They aren't getting anything they don't already have I guess.)
* They need perfect information retention for refreshing to be useless. I don't think they have that.
* I didn't intend to refer only to them. Not going to donate ever again. That's just an information proliferation thing.
It's sort of like how I know that my SSN is out there because of Equifax, but I still don't post it on gas station bathrooms with other info.