It looks like the UAW is making a stand. They are tired of making all the concessions while the management fat cats who have managed the company poorly get rich. Seems like a reasonable position to me. Let the management fat cats take cuts to their salary/benefits in order to save the company.
Alternatively, maybe the UAW president has been in touch with some politicians who have assured him a bailout is coming so he comes out firing in order to take the initiative. Negotiating 101.