Since 2020, Chile’s intercultural bilingual education policy has required schools in ethnic contexts with low linguistic vitality to teach indigenous languages and cultures. This transformation responded to calls for expanding this educational policy, allowing the rethinking of its foundations and purposes. In this framework, the present study addresses the implications of teaching the Kunsa language and Atacameño culture in three schools in the Province of El Loa, northern Chile. The study uses an ethnographic approach to describe the teaching process through participant observation, in-depth interviews, and documentary analysis. The findings show that teaching Kunsa language and Atacameño culture focuses on testimonial and schematic learning rather than linguistic and culturally dynamic learning. Paradoxically, in culturally diverse educational settings where a heterogeneous student profile predominates, this type of teaching can be configured as a pedagogical practice of assimilation or invisibility of cultural diversity. We suggest that teaching should be linked to the daily experiences of students. Thus, this would promote a more contextualized and critical learning in dialogue with the student’s individual and heterogeneous cultural belonging.