Legal Default for Adoption Gag Orders?

Maybe I'm a bit of a thickie, but I don't understand how this can be the case:

Jordan selected a couple, and when she went into labor, they attended the birth, along with her counselor and shepherding mother. The next day, the counselor said that fully open adoptions weren't legal in South Carolina, so Jordan wouldn't receive identifying information on the adoptive parents.

Surely South Carolina does not forbid adoptive parents from communicating with birth mothers or bar them from specific speech. Doesn't this really mean that South Carolina law does not mandate open adoptions and so adoptive parents have the ability to keep certain information from a birth mother? (I.e., the parents here are choosing to be jerks?)