Colleges and universities nationwide were already facing a challenging landscape before the pandemic, but the fall of 2020 is testing them in ways they never could have anticipated. Some are doing remote-only learning, some are hybrid, and some are fully in-person. And this academic year could be the tipping point that potentially upends the entire higher education sector. According to Jeff Selingo, the former editor of the Chronicle of Higher Education and author of “Who Gets In and Why: A Year Inside College Admissions,” institutions may need to rethink the way they serve their students, if they want to survive.