Doesn't a strike need an authorization vote? Perhaps they couldn't get one. United Airlines has over 90% vaccinated employees. If the numbers are similar at Southwest, it might mean there isn't enough will to oppose the mandate through a formal action. That puts union leadership in an awkward position - they could say "some employees have gone rogue and taken sick time to protest the mandate", but that's kinda throwing some of their members under the bus.

> they could say "some employees have gone rogue and taken sick time to protest the mandate", but that's kinda throwing some of their members under the bus.

I suspect it would be a far better alternative than what happens if it turns out the union was used to organize a walk-out, although I don't know what the ramifications of breaking those laws are (criminal charges? union disbandment?)