The value of ESL has been proved by many language scholars and researchers. The question is how this ESL program can work with each individual student. In reality, some students are successful with ESL, while building a strong foundation for further studies, and others feel ESL is not necessary for them. Thus, it really depends on student's readiness for further studies.
If a student is not ready enough (of course this can be seen with the lack of TOEFL scores, SSAT, or other testing results), a school usually decides what students should take. I would recommend parents and students to respect school decision especially on language evaluation unless you have some other proofs on language acquisition that students can present. ESL for students with lack of language no matter how long it would take could be very helpful.