I'm sure there are biological parents that don't want to know their offspring. Or have any responsibility at a relationship with them. Maybe those parents have been able to start a new life and now have families and don't want an intruder to uproot their lives.
There could be some sort of sealed documents that both parents and children can put in their information and if there is a match, and they both want the information then it would be available. I'm not sure how that would be done.
A Safe-Haven box was just used the other day not too far from where I live. It makes the news around here, but I was surprised it was the second time it was used at the same fire station since it was installed.
Seven babies have been surrendered via the baby box in Indiana so far this year, and 37 have been placed in a baby box nationwide since 2017.