I don't think so. The defense is simple. The general rule is that employers are immune from suit. This is the quid pro quo for workers comp where "injured on the job is compensated, no questions asked."
I'm not saying there won't be lawsuits, only that the cost will be modest/tolerable to the employer. Cheaper to defend the suit than pay the fine, that's for sure. Any extra cost, just pass on to the customers.
You really do not know what is coming, do you?
You think this is only going to cause a small speed bump for employers of more than 100 people? Pay attention the the resolve of the employees at the below link.