Many children maintain contact with their biological families if the adoptive family decides it is in the best interest of the child. This is discussed with the social worker during the adoption process and ultimately is a decision you make as a family.
Once an adoption is final, you are the child’s legal parent. In fact, Wisconsin has some of the most stringent adoption laws, which favor the child and the adoptive family. Biological parents can change their minds after adoption, but that does not change the legality of the adoption.