FWIW. The situation currently for anyone employed by XYZ Airlines etc. is that the cards are stacked in favour of an employer (and not through the airline or individuals fault). I think if you have a role still and despite the cut in salary, I would stick it out but be very certain that unless when things improve (timescale not clear), your employer then fails to match what the employment market dictates - get out and let them learn the hard way. If they fail to adapt afterward, then they will by default lose the good people they had and dwindle slowly to nothing.
If your employer is trying to do things like lock people in to contracts that limit earning potential for the next 2-3 years, then I would suggest this kind of thing to be a 'red flag'. It says to me that they are looking to recoup entirely the profit from workforce salary as opposed to sharing the pain. But it is of course a business and best to not take it to heart perhaps - take money and move on when the market allows. I would expect a decent employer to communicate with the afflicted workforce every say 6 months with at least a cursory review and update, and this would show good intent.