Yes I think so. There are so many resources and strategies to help educators teach ESOL students and for students to use to learn another language. In a school, it's not fair for only teachers who are bilingual to have all the bilingual (or ESOL) students in their class, as it might slow down the instruction time - especially for the students who are not bilingual. There are many benefits for ESOL/bilingual students who are in mainstream schools/classes too. Although a teacher isn't bilingual, she/he can still teach students who are.

I think teacheres who do not speak another language are able to teach a bilingual student. Teachers can use tranlate tools to provide the bilingual study materials in advance. In the class, if teachers often use Spanish or even Chinese to talk with EL students, it is unfair for other students because I believe English is still the main language.