Only time employees leaving is a bad sign had been when the company had been in zombie mode too long(few years) and haven’t delivered anything yet or still in alpha/beta stage with crappy deliveries no one is using or has no significant uptake.
Also, if there are financial difficulties, then a lot of people leave in droves and some actually come back after finances get better.
it's like you wrote this comment yesterday, and not in the context of what has happened