If I understand you correctly, that’s what my kids district did as well. Once you were in the school, you were in. Regardless of open enrollment changes in the future.
Yup, that’s apparently the same policy as my wife’s district. You open enroll the first year, then after that you are apparently enrolled as an “in-district student” and no longer do any of the open enrollment paperwork. For that reason we’re not too worried about location, per se, but want to be close anyway.