According to Wrestling Observer Radio with Dave Meltzer, talent within WWE have been looking for creative ways to be released from their contracts. Some talent have considered purposely failing their drug tests or faking injuries. Meltzer suggests WWE would freeze your contract before they release you for medical issues, though. He does believe that there is one thing you can talk about to guarantee your release: Unionizing.
Corporations have been known to make drastic moves to avoid seeing a union. Bigger companies than WWE have shut down departments and sometimes entire stores just to avoid their employees unionizing. Anyone who has ever started a job at Walmart knows how afraid they are of the word “union,” even going as far as making new employees watch an anti-union video during job training.
There have been signs of WWE talent fearing the topic of unions being brought up in the past, such as this interview with Bayley where she frantically sidesteps the topic as a positive thing or the time Hulk Hogan ratted on Jesse Ventura for talking about unionizing in the 1980s that nearly cost him $800,000 in royalties, to name a few. The WWE would fire you than risk a union, realistically.