I wouldn't count your AI chickens yet. Path dependence is real and SAG/WGA are smart to pick this fight today not in 5 years' time. If they play their cards right now, while they have leverage, then they will gain additional legal/contractual leverage for the future.

Slavery and child labor were once common and economically lucrative, today they're very rare in the developed world. It's simply not true that humans can never choose to collectively reject an economically compelling option.