Beauxbatons and Durmstrang

Beauxbatons and Durmstrang enter the story as guests. One is associated with a brighter, more formal glamour. The other with a colder climate and a reputation for teaching what other schools refuse. Both impressions are carried by entrances, uniforms, and a handful of students.

They matter because Hogwarts is not the only campus. The world is larger than one castle, even when the plot rarely pays the tuition elsewhere.

Anything precise about their syllabi, beyond those impressions, is speculation. See the Margin before you promote a fan syllabus into a fact.