Or these employees have consciously chosen that they'd rather the knife come, if it's going to come, sooner than later.
The notion that them speaking out now proves that they have nothing to worry about is ridiculous. If nobody had spoken out, that would also have been used as proof that everything is fine.
In short, are they speaking out against real offenses, or merely hypothetical ones?
If Brendan Eich being CEO means they are not able to perform their duties as stipulated in their employment contract, they should resign.