Even if he DOES render strike action ineffective, he will make BA a pretty poor career choice in the future.
Making CC a pretty poor career choice is exactly what WW wants. This is about New Fleet in everything but name.
New Fleet will recruit young people, full of energy and enthusiasm, who will fly for a couple of years before moving on to a 'proper' job where they will use their degrees and qualifications and languages and earn a salary which will allow them to take on a mortgage and settle down.
BA is up against Middle Eastern and Far Eastern airlines and the LCCs in Europe who are already hiring people like this. They offer wages and conditions that make the idea of a 'career' as CC only a pipe dream.
BA is going to offer market rates +10% to ensure they get the very best applicants. An attractive job, yes, but a career it ain't. Ask all the CC posters on here who do NOT work for BA.