In a bilingual program at a junior high school in Toucheng, Ms. Kuo is teaching a social-studies-integrated English lesson on global migration patterns. She invites students to first brainstorm in Taiwanese or Mandarin with a partner about migration stories in their own families, then articulate the main themes to the whole class in English. Throughout the lesson, she welcomes contributions that weave English with Mandarin or Taiwanese, intentionally drawing on all three languages as resources to develop students' analytical understanding of migration concepts. A fellow teacher observing the class remarks that Ms. Kuo is merely tolerating language mixing because the students lack sufficient English proficiency, and warns that this practice contradicts the aims of the bilingual program. Which concept most accurately describes Ms. Kuo's pedagogical approach, and why is the fellow teacher's interpretation problematic？