Basically. To decertify the union a petition needs to be filed with the NMB and a vote is cast. However, considering that this whole rumor is about the full integration of SKW, XJT, and ASA, I think it would be tough to get 51% out of a group that is 2/3s unionized.

ALPA is not perfect, that's for sure. But I think the majority of pilots would rather have the backing of a union than not. Otherwise I doubt SKW would be one fo the few remaining non-union shops left.