The union absolutely will support you. The difference is it's possible they could be arguing a termination grievance rather than just a contract violation.

Is it likely they'd fire someone? Probably not, but your guess is as good as mine. Is it possible? Sure, go read section 5 of the Pilot Employee Handbook and 26.U of the contract. Would you get your job back? Most likely. In the end the question boils down to how long do you want to risk not earning an income?