Maybe they feel they can do more from outside the country?

I think you missed the point of what they were saying. As with when the Nazis gained control in Germany, they need to get out sooner rather than later, or their work may get them jailed or killed.

The student they mentioned who was kidnapped off the streets by a masked gang simply co-authored an article. That was it. Her visa was revoked.

We will hear more about disappeared journalists, educators, students, and protestors the longer this regime is allowed to rule.