Let's be real, if capitalists could make you work in your sleep, that's just going to be added to your existing work. There's zero chance it replaces 9-5. The reality is that we've already made stunning leaps in automation since the industrial revolution, but none of that translated into people working less.
Also, I'm not a neurologist, but I'm going to go out on a limb and suggest that hijacking your sleep cycle that evolved over millions of years to allow your brain to rest in order to do work will likely have some spectacular negative consequences.