Well via different categories by happenstance perhaps, which is why I mentioned marriage. But then again people on tourist visas do that too, probably in bigger numbers. And tourists from most places can't visit right now either.

Most pathways to immigrate to America are either capped, backlogged or hard enough that there isn't a ton of people using them.

If this was a strategic move by the WH rather than just ICE interpreting rules, I'd be much more willing to believe this is an action targeted at China given how many foreign students are Chinese. Or as someone else noted, a way to pressure schools to open up.