After you have approved the new owner and home, IMO it's better if the new owner picks him up and takes him to his new home if possible. I just think the dog forms a quicker and stronger bond if his new human physically takes him to his new home. I've adopted all of my dogs (all from breeders) and that's the way I've always done it. Just my opinion.
'If you find a way to enjoy the ride, it doesn't really matter where you end up'
5 GSDs at the gate: Katie, Iroc, Red, River, Jake