I'd imagine a good bit of these students have pretty extensive lives and plans in the US since they're here LEGALLY.
This is a blanket statement about ALL mexican immigrants, and "you" refers to his entirely white base of supporters. The administration set up deliberately cruel and trauma-inducing family separations out of hatred, just as these policies are born out of hate. When backwards people talk about "illegals," they are never talking about people's legal immigration status, it's shorthand for race.
International students basically are not "stealing" Americans' jobs. They're creating them, in fact. They're high-dollar tourists, basically.
As for things that are "temporary", it's looking like the pandemic situation isn't changing any time soon unfortunately. I think everyone is just adapting. The govt is saying going totally online cannot become the new normal for internationals.
Students are certainly able to transfer, by the way. I know students who failed and rushed to apply to yet another school (they always find one too) to avoid being sent home as a result.
But yeah, this is very sad.