If you’re like me, you could find out at age 38 who your true biological father is, and contact him for the first time. It may spiral you into an identity crisis, wondering if you should change your name and the name of your children. Here’s the thing though, my biological dad didn’t share his DNA. His first cousin did, and I contacted him.
As others have said, because you share your DNA with all of your relatives, it’s already not 100% private. One or more of your relatives has already tested their DNA. The most genetic privacy you can get would be for nobody to know who you’re related to. How tightly do you protect that information? Changing your name would be a good first step.