bio family rights

The TPR on our nephew/now son was different for each parent. For biomom, rights gone for her and her whole family. For biodad, my BIL, rights gone for him but not the family; I guess because ds was coming to live with relatives--us. We adopted one month later. We keep in touch with maternal gpa as well as my MIL. If foster/adopt, I imagine TPR means bioparents rights gone and all connection to biofamily also legally gone. Interesting thread--