I think it's just the term that they don't recognize. Any new syndrome has to be around awhile before it makes it into the official lists and so on. However, that doesn't mean that they don't recognize that this behavior from a parent would be emotionally and mentally damaging to the child. The information in the first link you gave shows that it is. I don't think a psychologist would doubt that this behavior from a parent is harmful to a child.

In court, probably your friend would need to have psychological evaluation of the child to show damage and psych eval of the father. This could be ordered by the court. Your friend might have to undergo psych evaluation herself so as to make it reciprocal (psych eval of both parents to determine their fitness to parent). It is not necessary that the term PAS be used in order for a psych eval to be done and emotional harm to be found. It might be best to leave this term out of her efforts, since the lawyers might get hung up in symantics if your friend insists on using the term. Better just to go with evidence like symptoms and harm done.