Will the Right to Disconnect be of any use?

I don't think, at present, any company officially requires it's employees to be available after working hours but they still have to otherwise their boss/manager will get his ego hurt. Even if this bill becomes an act, how will it prevent managers and bosses from still exploiting their subordinates with threats of bad performance reviews and basically from playing with their careers?

I think this bill is mostly useless. What do you think?