No, that's not how the law works. There's a lot of work material before the law is decided that's used as guidance as well as predecents in courts and other material. All aspects are of equal value no matter how they're named.
Yeah, it gives the children an opportunity to voice their own opinion and it will be given weight in any decisions made by social services. Their opinion is not just brushed off because they're a child, it has to be taken into account.