This sweet boy is listed on Reece's Rainbow as Riordan.
In international adoption, children with special needs most often are not orphans. They are very often relinquished to the state at birth or when their disabilities become apparent. Sometimes this is due purely to prejudice against people with disabilities, and their families don't want them because they have special needs. But sometimes it is because they don't feel equipped to care for them, and their society doesn't value people with special needs and doesn't make a place for them (other than in mental institutions... even if the child's need is purely physical). Some of these children have relatives who visit them periodically. Usually the children whose families are still involved in their lives are not available for adoption. It makes sense that if their families are still involved in their lives, and want to remain parents to the children, and that way the children can remain in their own country and culture.
Other times, parents look at the lives available to their children in countries with few resources for children with special needs, and the richness of acceptance and education and opportunity that is offered to children with special needs in countries like the US, and decide that adoption is the best decision for that child. Much like most parents in the US who choose to make adoption plans for their children, they want their child to have a better life. They want their kids to have things that those kids can't have with their first parents. In the case of international adoption, that means a society that accepts them, makes a place for them, and is invested in seeing them live up to their potential, and parents who can advocate for the little boy or girl in his or her new country and make sure that happens.
It sounds like Riordan's family is one of those families that have decided that as much as they love their son, they need to choose international adoption to give him the greatest range of opportunity in their life. Riordan's profile says that his family is involved in his life but he is free for adoption.
It is rare in international adoption to have the opportunity to have a relationship with a birth family. Riordan's adoptive parents will have a great opportunity to get a sense of who he will look like, learn more medical history, and be in contact with people who are still immersed in his birth culture. They will know why his family made their decisions and be able to give them peace about it by sharing his progress with them. Growing up, Riordan may be able to learn about his birth family firsthand instead of reading dry reports, guessing, or wondering. Biological parents and heritage and genetics are important--to adoptees just as they are to the rest of us. I think it's awesome that Riordan will have that opportunity. If this is the kind of adoption you are looking for, maybe Riordan is your son :)