I don't see why the union would necessarily be pitted against the employer in tech. Yes their goals are not perfectly aligned, but that sort of work environment is something that both benefit from so I don't see that disappearing.

With a more centralized organization as a check on management decisions, the employer can find out earlier what the employees will tolerate by asking the union representatives (and not have the employees walk out when an unappetizing project is discovered). I expect the AWU would also fight against the reduction in transparency across the company, as that is a common concern among people I know that work there.