(A) As used in this section, “public school preschool integrated class” means a class that is operated by a public school, educational service center, or county board of developmental disabilities in which fifty per cent of the students in the class are children with disabilities.

(B) Notwithstanding any change to administrative rule adopted by the state board of education prescribing licensure qualifications for teaching a public school preschool integrated class, a teacher who is licensed to teach special education and is employed to teach a public school preschool integrated class on the initial effective date of any rule change prescribing such licensure qualifications may continue to teach a public school preschool integrated class until the teacher retires, resigns, or is reassigned by the employing school, educational service center, or county board of developmental disabilities. Following the retirement, resignation, or reassignment of the teacher, the teacher must meet the licensure qualifications prescribed by administrative rule to teach a public school preschool integrated class. Upon retirement, resignation, or reassignment of the teacher, the school, service center, or county board of developmental disabilities shall employ only a teacher who meets the licensure qualifications prescribed by the rule to teach a public school preschool integrated class.