In a current world, manager says: "We have great work-life balance, feel free to work as much or as little as you want! Also, here is an assignment, if this is not done by Friday I'll PIP you, then fire you and you'll get deported. Wink wink, you might want to work more."
In a timesheet world, a manager tells the employee: "Sorry, I cannot approve overtime for you, because I care about you! Also, here is an assignment, if this is not done by Friday I'll PIP you, then fire you and you'll get deported. So make sure you don't record more than 40 hours, but remember we don't really know how much you spend working (wink wink)"
This law might eliminate those insane AI startups which openly advertise 996 schedules, but most requirements of overtime are not that overt.