In the current tight labor market I doubt any employer wants to fire employees over a federal mandate that some workers oppose. Firing people shrinks your company and your stock price. Employers will find ways not to fire their people unless they already planned to downsize.
UA set its own mandate (didn’t hide behind mommy’s skirt) and processed separations to those that didn’t comply. And because they led, the numbers impacted ended up being tiny.
How would you characterize their action?