Tableau Server is currently open to all faculty and staff ... members are eligible for a free one-year license to Tableau Desktop and Tableau Prep for teaching and non-commercial academic research.

This helps Tableau (or in the case of students, the verification supplier) confirm eligibility for the free offerings. Here is Tableau for Teaching FAQs for reference.

Tableau has a free badging system for classroom settings, students and nonprofit higher education teaching and research. Through the Tableau e-learning program, you can receive Tableau, Tableau Prep ...