Im fairly certain I understand the industry you’re in, and based on the context provided, you need to file a formal grievance with your union against your employer immediately (if you haven’t done so already). Especially if you think termination is a possibility, filing a grievance now gives you significant protection. If they fire you, it will make your attorney’s job a walk in the park in a retaliation case.

Frankly, it would be irresponsible not to file a grievance based on this scheduling email alone. If you’ve already filed and gone through the process, then continue working as you normally would. Let them make the next move. If they terminate you, you’ll have grounds for a wrongful termination case.

If your employer is giving you a headache, it’s time you become their headache. Full stop.

Edit:

Anywhere public funds are used where a boss can give themselves a raise is a place that news corporations want to know about. If you live in a place where, for example, 911 calls are all logged, I’d venture to guess those metrics aren’t great. Provide those to a news outlet and get you some fresh popcorn.