They are still allowing unvaccinated students on campus; however, they will not be allowed to move into residence halls. Southwestern requires all first-year and sophomore students to live on campus unless they live within commuting distance of the university so this may provide a means to disenroll students.
Unvaccinated students are required to self-quarantine for 14 days if they get COIVD while vaccinated students are required to isolate for 10 days. There are no provisions for remote learning, although I expect that some of the professors will probably bend to allow the students to take tests. However, the timelines at the end of the semester are extremely tight. There may not be enough time to take an "Incomplete" grade and have it replaced a few weeks later with a letter grade. Therefore, every student is wagering that they won't throw $20K away by getting COVID near finals.
All students, faculty, and staff are required to wear masks indoors. All indoor social functions are limited to 100 people.