So this is interesting; assuming that this doesn't go to the Supreme Court or is otherwise unchanged by it, it could mean that after some states implement their own laws (and fight off the inevitable lobby/lawsuits attempts to stop from from doing so ), this could go down two ways:

1) The ISPs create two (or mor) versions of their packages that they can offer/operate in different states - this would be quite expensive (and I suspect in some cases quite difficult too), but it would allow them to leech extra profit off the hides of customers not protected by state law; it would generate a bit of outrage when users see their family and friends in other parts of the country are better off, but I doubt that will make the whole system collapse

2) Or they will give in and accept the higher(highest?) standard, similar to what's happening for car emissions. I am maybe too cynical, but I doubt that will happen so easily.

Car emissions are a secondary thing for manufacturers - they can grumble, but at the end of the day it's just a bit of extra cost. The repeal of net neutrality is a matter of life or death for ISPs - it's what will make the difference between them being able to maintain outsized profits and power in their nice little oligopoly, vs becoming dumb pipes.