Section 3 of https://nshe.nevada.edu/wp-content/uploads/file/BoardOfRegents/Handbook/title4/T4-CH15%20Regulations%20for%20Determining%20Residency%20and%20Tuition%20Charges.pdf does not exclude international students from being exempt from non-resident tuition through graduation from a Nevada high school.
The residency form at https://www.unr.edu/main/pdfs/verified-accessible/divisions-offices/student-services/admissions-records/nshe-residency-form.pdf says that option 1, 2, or 3 must be completed; option 1 is where the graduation from a Nevada high school is listed, and does not exclude international students.