When you paid, you accepted their rules, like this one.
I would love to get back at least part of the money I paid over more than one decade of playing this game. Even getting money back for the rubies that I still have would be nice. But, I gave money under a clear "No refunds" policy, and no lawsuit would be able to cha(lle)nge that.
They can shut the servers down whenever they want to, just like they did it with Yahoo, Kabam, and - a bit over a year ago - Russian servers. I don't see a flood of lawsuits. Do you?
In my personal opinion (i.e., I do NOT write this as a mod and it's not official, because I have no official info on the matter), I believe that the game is on life support, that they do minimal supporting (which does NOT include fighting the bots; that'd be costly), and that the servers will keep running while the game is in net positive money (i.e., it makes them more than it costs them). It's that simple. No need for silly conspiracy theories.