If the child CHOOSES to disown his own family and chooses to cut off all contact with them, that's then his choice, but I doubt there are many families who would not welcome that child back with open arms if that child came to his senses and came back to them.
Come to think of it, that would make a great parable. Maybe Jesus should have thought something up like that to illustrate God's great love and mercy for us.
Oh, wait a minute.......
Psalm 103 6The LORD works righteousness and justice for all who are oppressed. 7He made known his ways to Moses, his acts to the people of Israel.
8The LORD is merciful and gracious, slow to anger and abounding in steadfast love. 9 He will not always chide, nor will he keep his anger forever.
10He does not deal with us according to our sins, nor repay us according to our iniquities. 11For as high as the heavens are above the earth, so great is his steadfast love toward those who fear him; 12as far as the east is from the west, so far does he remove our transgressions from us.
13As a father shows compassion to his children, so the LORD shows compassion to those who fear him. 14For he knows our frame; he remembers that we are dust.
Praise God.
Yes they would most certainly welcome them back IF they came too their senses. That is the keyword REPENTANCE.