Re Manhattan, I read that NCL had (erroneously) told their passengers to not begin the Bermuda application process until within two days before departure. This, of course, overwhelmed the system, and led to the big delays. Those pax who didn't even know to do it added to the delay, and if some were unwilling to do it (incl pay their $40), they could certainly be left behind.
RC has informed pax to apply well within 30 days. Some could still arrive unaware and unprepared. But I still find it hard to believe that 200 were just dumped at Baltimore. The only answers I get are "I was on the cruise, I know it's true", but then "No, I wasn't dumped, and I don't know anyone who was". I gather the unprepared were taken out of line to wait for separate processing.
I guess I will find out next week!