I hate unions but it's abuse like this that reminds me why unions exist at all. Unions basically tell managers that there are rules of engagement they need to respect. And they tell companies that a level of work needs to be guaranteed to them for employment, arbitrary rules will not work, and employment is playing with a life and you need to plan ahead for that.
Sure certain employees abuse it and it attracts other types of employees that could never work at startups. And a guy with his own YouTube channel would rather work for a real company than a unionized one. But there has got to be a balance. Between unbridled employers and managers and systematic ones.