One concern with that would be that good engineers would usually see this on the horizon and leave for better / more prospective jobs in advance. So those who stayed until mass layoffs might not be the top talent that used to work at the company before when it was doing better.
I am not sure it applies in this case as this was quite sudden and we don't have enough visibility to see how many red flags were there few months / a year ago. In this case it seems to have been so sudden that lots of great people have been caught off guard.
There are actual a host of real life circumstances such as family, babies, health etc. that might prevent or make it difficult for someone to conduct a preemptive job search or job change.
I am not sure it applies in this case as this was quite sudden and we don't have enough visibility to see how many red flags were there few months / a year ago. In this case it seems to have been so sudden that lots of great people have been caught off guard.