In this case, the students would be returning home, and therefore be citizens of the country they are flying to. Generally speaking (including the EU, which you mentioned), citizens are exempt from the travel bans. Even during the quarantine, there were once-a-week flights to China from the US (https://www.cnn.com/2020/06/16/business/us-china-flights-int...)

Not saying that these changes aren't horrible, they are, but I don't think getting home is impossible. Very difficult, in most cases yes.