[rlucas]

The moment they stop accepting reservations for new travel outbound is the moment they are commercially dead.

Agreed, if you knew there was 0% hope (say, of flying anyone back a week hence) it would be unethical to keep it going. But if you were trying to keep things afloat and thought you could do, it would be unethical to do otherwise, since stopping new outbounds would 100% doom the firm and strand the overseas travelers.

[Scoundreller]

I guess the question is: how often have airlines/tour companies been at the brink like this and pulled through?

If the answer is “close to zero”, we need to rethink this privilege.