20% certainly seems to be a number thrown around a lot at the moment, seemingly with no foundation. Someone in BA mentioned 80% capacity by Christmas - this does not automatically mean they're about to chop 20% of the airline. What about after that?
It's difficult not to chastise oneself over decisions made that in retrospect now look like the wrong ones. I dare say I'd have been considerably more secure at my previous airline than where I now sit on the MSL at BA. You make the best decision you can based on all the information you have available at the time. Had you turned down a move based on fear of a global pandemic threatening jobs, you'd have been branded insane.
Ultimately no-one knows how this will ride out. If there's a vaccine developed in the timescale some reports seem to suggest, it may not be as long as some of the pessimists would have you believe.
As has been mentioned I expect lots of options are being looked at, in every airline, to protect as many jobs as possible. I sincerely hope that pilots at the top of seniority lists, with no mortgage and big pension pots, are having a long hard look in the mirror right now.