Depends on district policy and state/local law. E.g., in my kid’s district a parent can request for their child to attend any school of the same grade within the district if space is available, but parents have to provide transportation if it’s not the zoned school. For the district where we lived previously, a family moving out of zone could request that students be allowed to keep attending their current school through the end of the year.
Per the article, both state and federal law allows these kids to continue attending the same school in such situations. It’s the school’s fault because, even if their district has no such policies, the clear and obvious course would be to seek an exception until policy could be addressed to align with the law. Instead, they simply refused to meet with the mother.