If they're prohibited from treating credits from non-regionally accredited schools differently, then I suspect schools will put into place policies that are not "blanket" policies, but instead policies that dictate individual evaluation of each student, which will turn out to accomplish the same thing. Which really wouldn't be great, but also would filter out a lot of people of questionable academic credentials: regionally accredited schools generally meet some minimum standards, while non-regionally accredited schools are a crap shoot: some are just fine, but many are awful degree mills that don't even grade work beyond assigning an "A" for any submission.