>Under the RLA, our Union is forbidden from taking job action to resolve labor disputes under these circumstances
They couldn't admit it if that's what they're doing. They'd have to deny it either way. Even an "unofficial" unorganized sick out.
On the other hand- if a pilot knew he was getting fired in two weeks for not getting vaccinated, and he happened to have two weeks sick pay, well then the company policy did all the "organizing" that needed to be done.