This is why I want a genetic sequencing lab that will sequence your genome, send it to you encrypted by your own public key and once you confirm receipt and verify it is valid, DELETE IT COMPLETELY. Along with the record you were their customer after the 6 months or whatever required for waiting out chargebacks.
Then you can analyze your DNA with a desktop app that doesn't send out any data.
For GEDMatch, Ancestry.com, 23andMe, etc, most of the value comes from being able to aggregate many people's data. If they had to delete it after collecting, they'd have to charge a lot more, and there's just no market for that.
Perhaps they could anonymize the data (at least, purge foreign key references to account/billing info) after 6 months, but not delete it.
Much like you can't anonymize browsing history data, email metadata or financial transactions -- I suspect DNA information also cannot be satisfactorily anonymized.
Then you can analyze your DNA with a desktop app that doesn't send out any data.
The deleting part is hard to find.