So it's an alarm clock that checks your subscription is still active before waking you up. Welcome to the future. I hope AWS doesn't go down around 6:45am.
No. It's just a pre-sale for members. From below: "For a limited time*, paid Nintendo Switch Online members in the United States and Canada can purchase Alarmo online via the My Nintendo Store before it is available to purchase by the general public."
I think the subscription is just required for the pre-sale before general sale. I really hope you're wrong about the sub being required for the damn thing to work, but it would not surprise me.