While that looks good on the surface, I'd bet that the reality will be different.
Employers, for the most part, do everything in their power to keep expenses to a minimum. One expense that they can reliably control is labor costs. If that proposal would go into effect, I can see employers cutting hours to anyone covered by that proposal. They might hire extra employees to cover the shortfall, but those positions would be part-time, no benefits and lower wages. 20 hours at time and a half plus associated benefits vs. 20 hours at 80% (or less) and no benefits is a no-brainer for the average employer.
Alternately, the employer may just decide to let those hours go unstaffed, and thus make the job harder on those actually working.