I think that the significance of having to educate students with linguistic diversity is that it tests the teacher. The modern classroom is a heterogeneous one, filled with students that have different narratives and embrace different backgrounds. The modern teacher has to have the skills to be able to effectively instruct all students. This includes those who are linguistically diverse.
In a way, the linguistically diverse student challenges the modern teacher to be better. The student who has different linguistic or cultural backgrounds represents a horizon for the modern teacher. They must leave their comfort zone and forge an educational connection with a student who would normally be marginalized. It's not easy. For example, if a teacher is embedded in Common Core instruction, or canned reading programs that address all the students in the classroom except the linguistically diverse one, total success is not recognized. It becomes critical for the teacher to be able to reach out beyond their own comfort areas and seek to bring a student who might be marginalized into the instruction process. It is here in which there is relevance in educating students with linguistic differences. New strategies must be employed. Different techniques must be attempted and individual dialogue has to be broached. All of these are uncomfortable, but it is here in which students who are linguistically diverse become the test for the modern teacher and it is here in which they are significant and relevant. They become a point of demarcation in the horizon of the teacher. If the modern teacher wants to be considered effective with all students, they must be able to reach across all lines and be able to educate students who are linguistically diverse.