Earlier quoted context omitted.
Not even a new management team: an existing management team can change things, too. But, so what? You can just work elsewhere instead.
As a manager it should be terrifying and strike fear into your heart at the thought that your entire team's last recourse is to just up and leave with no notice. With a union you can bargain, understand the problems, and resolve them.
If the organization that I work for creates an environment that is not conducive to retaining employees then I’m just as likely to leave as my team.