It makes sense that if the primary motivation for offering an easier route to immigration is to ease shortages in certain critical areas, the route should only be offered to those areas.

So, yes, if there are enough citizens and permanent residents meeting the current requirements and enough in school to meet projected demand, there's no need to offer a faster route in those fields.

They are not useful, sorry. They are vanity professions. All of the anthropologists in the United States could be abducted by aliens from Alpha Centauri tonight and we wouldn’t notice a difference in the morning. If all of the semiconductor professionals disappeared in the same manner we’d have serious problems.

I’ve got nothing against anthropology as a field or anthropologists themselves, but they wouldn’t even show up on the tech tree. You don’t need a PhD to be a school teacher and, frankly, we would be a lot better off if instruction was done by practitioners instead.