Most graduate students are in the US on F-1 visas [1] and still need to maintain a minimum course unit enrollment per semester in order to be in status [2]. IANAL, but I would assume they're not exempt from the new in-person requirement for their registered courses.

[1] https://educationusa.state.gov/your-5-steps-us-study/apply-y...

[2] https://ois.usc.edu/students/maintainingstudentstatus/, https://international.northeastern.edu/ogs/maintaining-statu..., etc. (many schools have some version of this FAQ page on their websites)