We have no idea how many other employees agreed with the five, and the point is that we'll never know, because the precedent of "speak up and you're fired" has now been set.
Being an autocrat doesn't mean getting rid of everyone who disagrees with you, just the ones who dare to do something about it (or potentially might).
This case reminds me more the classic boycott handbooks. A tiny group of people sparking the flames of revolution for no reason, maybe desperately trying to get the attention of Musk, maybe for profit.
This people can sink a startup really fast. The kind of people drawing caricatures of the CEO where they should be doing calculus on critical parts of the system. Letting they go is the correct move. They are 100% free to fund a better, more moral and more ethic Space-Z with their own money and promote a CEO that they like more.
You are forgetting that the Stasi needed quite a lot of concrete and border guards to keep people from leaving and that the whole thing collapsed in the end in a peaceful revolution because the people didn't want to take it anymore.
It sounds like most Space X employees are doing fine. And we are talking about an example of "soviet management" here?