There is a simple reason. After the college entrance examination, after you know your score, fill in your volunteers according to the situation, and the provincial examination institute will file according to your wishes. Because the number of people filing is unpredictable, there may be cases where you have not filed, resulting in the failure of the list. This situation is very common. Because the entire voluntary reporting is led by the Provincial Department of Education and implemented within the system, it is impossible for the school to intervene. Therefore, it is not reliable to guarantee further study.
In reality, many famous schools sign pre-admission agreements with high-scoring candidates. In fact, it is not the school that binds them, but the students, hoping to recruit high-scoring candidates to their own schools. The content of the agreement also requires students to fill in their own school volunteers. However, high-scoring candidates will generally sign such agreements with many schools, so some schools will definitely be stood up in the end, but schools cannot be held accountable for breach of contract.
What is the reason? Self-admission is not a civil act, but an administrative act, which is not regulated by contract law and civil law.