It is not at all out of line to say "the airlines should not have spent $45B (or whatever the amount was) on stock buybacks, they should have saved a reasonable amount in anticipation of the next crisis" even if this particular crisis is much worse than anyone would have been able to anticipate a year ago.

Even if they had only kept, say, $20B of that money—reducing their buybacks by less than half—that would surely be $20B they would not now be asking us taxpayers to spot them, and it's possible they would even be able to make a different kind of plan using that $20B to stretch them over at least some significant part of the gap.