Well, if the publishers can successfully sue for damages and win, my guess is that the problem will be swiftly addressed.
I think "and win" is the key phrase here. A tiny publisher going up against Amazon, even with an ironclad case, is still going to have to fight a long and expensive uphill battle against Amazon's army of lawyers and every legal tactic at their disposal. All Amazon has to do is make litigation so expensive and time-consuming that the small publisher can't afford it; they don't actually have to win.
The really sad thing, though, is that even if the publisher in question had a big war chest and the case made it to court, I'm not sure Amazon would lose. For better or worse, copyright laws in the US are pretty lenient toward online service providers when the infringement is carried out by users of their services. Sometimes this is a good thing, but in this particular case it could give Amazon legal cover.
It would be an interesting case though for sure.