I agree with you in principle. And I agree that the government has been steadily eroding our privacy. And I agree that California probably shouldn't be retaining these samples forever.

However, the likelihood of being able to "sequence" the biomatter on a blood spot is quite low, and the probability of getting good signal out of it continues to go down over time. It'll still remain useful for various kinds of spot testing and genetic disease testing, but it's not going to produce a fully validated genomic sequence or even be that useful for forensic purposes.

This isn't some sort of sealed blood vial, it's literally just blood on paper.