(1) If a student under the age of twenty-one years is allowed to enroll in any common school outside the school district within which the student resides or a school district of which the student is considered to be a resident for attendance purposes by operation of law, the student's attendance shall be credited to the nonresident school district of enrollment for state apportionment and all other purposes.
(2) The provisions of this section that are applicable to students under the age of 21 must remain applicable to students with disabilities as defined in RCW 28A.155.020 from age 21 through the end of the school year in which those students turn 22 years of age.