Nope. Lawsuits are not the way to establish or maintain a cirriculum. Neither are public schools the best way to educate the crowing glory of God's creation. But as long as they're there, decisions must be made that tend to the betterment of the students. In the case you mention, the swap is a bad one, whether by force of law or voice of persuasion.
Where one person's idea of betterment conflicts with another person's idea of betterment, hopefully a compromise can be reached that allows options. Heretofore the option of teaching ID in an academic setting has been opposed BY LAW from those who think the government ought enforce their idea of what is better. You know. Rome and all that.
No, I don't know what "Rome and all that" means. ID has been "opposed by law" in much the same manner that teaching astrology in astronomy class, or witchcraft arts in arts class, or Bondage and Discipline hygiene in hygiene classes have been "opposed by law".