Why just those you named? Why not Konstantinova, or Tsurskaya, or Feditchkina, or Lozko? Why do you think they will not want to send one of their better skaters? They can't send them all to junior worlds, so they may as well use the one who won't go to have an extra competition.
Because traditionally they haven't send their best girls to this competition. Last time they send Proklova who was a competitive skater but not a TOP skater. In 2013 they send Stavitskaia who also was a competitive skater but not a TOP skater. The same thing will happen this time also, so, no Tsurskaya or Fedickina.