On the one hand, it seems overtly xenophobic and anti-intellectual. On the other hand, I don't see why an international student needs to be in the United States in order to participate exclusively in online classes.
Even if the issue is a lack of human welfare (eg unsafe neighborhood) or necessary infrastructure (eg slow/inconsistent internet) back home, an international student could live somewhere else and probably save a ton of money in the process.
What am I missing?
I wouldn't want to expect a student in Sydney to stay awake at 3AM to follow a lecture at Harvard at 1PM.
The same is true for office hours with professors and TAs. You have a huge disadvantage in getting information if you are in a bad time zone.
People have year long leases. People have commitments. Even if they choose to leave, no doubt they would prefer to do it on their time, not with ICE breathing down their neck.
Airplane tickets are expensive and rare. It's fucking hard to just uproot yourself in 10 days if your school becomes online only.
Also, having your visa revoked ducks the OPT process, in case you ever wanted to work in the US in the near future.
The pandemic is far from over, especially in the US, a fact which is obvious to everyone. The retraction is pure stupidity. Of course it would be unreasonable to ask int students to attend in person classes given the situation.