<< Changing the law is extremely difficult in the US because of the gridlocked-by-design political system, so I think it's unlikely. Changing it would also be extremely unpopular.
I am thankful for this response, because it illustrates something OP pointed out directly ( as humans we mostly suck at estimating future risks ). Changing a law is sufficiently possible ( hard, but possible ). On the other hand, short of current civilization crumbling before our eyes, there is no timeline, in which DNA data already in the hands of some other entity could be put back in the bottle. Possible vs impossible ( assuming time machines can't exist ).
<< The point of my post was that me being harmed due to having given my DNA to 23&me is unlikely, not impossible. Just like it's theoretically possible a brick could fall on my head while walking outside, but I still don't wear a helmet every time I go outside.
I think the reality is that we do not know for sure ( although some fun science fiction does exist suggesting it is not a great idea to let that space be unregulated ).
That said, DNA, at its core, is just information. Information by itself is neither good or bad. However, humans come in all sorts of shapes, sizes and capacities for evil. In some humans, that capacity is rather shallow. In others, it runs very deep indeed. Evil is not a pre-requisite to become a CEO, but since humans can be pretty evil, it is just a matter of time before at least one is hardcore -- kicking puppies for fun type - evil. If so, that one evil person can do damage, if they so choose with information at their disposal. And the funny part is, there is just so much information hoarded and sold these days so.. really.. it is just a matter of time.
<< Worrying so much about this stuff just feels to me like the tech geek version of preppers who stock their house with guns and canned food in case the apocalypse comes (which never does).
I will not give you a speech here, but never is a really long time. If there is one thing that a person should have picked up since 2018, it is that things can and do change.. sometimes quickly and drastically. It is not a bad idea to consider various eventualities. In fact, DHS suggests it is a good idea[1] to think about your preparedness.
You might be mocking preppers, but I did not suffer from lack of toilet paper during the pandemic.
[1]https://www.dhs.gov/archive/plan-and-prepare-disasters