This is a really smart thing, though. Any unions that align contract dates with UAW and others who also do so, gains a huge lever to use both now and later.

He's speaking as a union rep, I get what you're saying but he just can't call a general strike. It would take years alone to get different trade union contracts to align to expire on the same year to get what he wants to do across. For example I'm in a steelworker union and my contract expires in 2027. If we sign a new contract in 2027 and participate in a general strike it wouldn't be backed by our union and could be punishable. However if they vote to extend the current contract 1 year near the end of the contract (very likely) we would actually have steelworkers and auto workers contracts expiring on the same year which could be interesting if these assholes actually communicated with each other union to union.

Sorry if you knew all this but I took your comment as in a "why not sooner?" or "what are they waiting for?" context so I felt compelled to answer.