That's the stupid part. Sure, they could sue. For what? It's bullshit overreach and they know it. But as you said, they're playing with unlimited house money, versus making the retailer pay out of pocket for counsel. An almost exact parallel to the 2A issues, which I am also a big proponent of. We call it "lawfare" (instead of warfare) in that community. Thankfully there has been a lot of good headway made on that issue lately, though still a ways to go. As you said, there is no grassroots National Cigar Association or equivalent, nor are cigars/smoking covered in the Constitution, so we truly are at the mercy of the state legislatures.
I am glad to see some companies telling CA to stuff it, though. I'm sick of them thinking they can control the entire market on various issues (gas cans, "Prop 65" warnings, diesel trucks, vehicle emissions, etc.). No offense to the CA members here, but that state needs to stay in its own fucking lane and let the rest of the country drive in ours.