Again, this is the same thing that Romer v. Evans was about, but with a twist – instead of directly nullifying local anti-discrimination laws, Kansas just said that employers are allowed to say their religion prevents them from following the law. It’s effectively the same as nullification, but the courts might not see it that way.
What is also interesting is seeing the other end of the “states’ rights” argument. It’s not just about the federal government staying out of state affairs, apparently, but also about the states micro-managing localities. It doesn’t make much sense, which probably means that no one actually cares about states’ rights and they just care about getting certain policies passed.