"Legacy" is a thank-you for paying for v1.x.

Months before ever announcing the Legacy program, SE required payment to continue playing. A lot of us began paying before we had any idea there would be any such reward. Once SE announced Legacy, they invited others to start paying to qualify, and spelled out the requirements and even the last day it was possible to qualify. SE was very open in this regard.

There's no 1.x left to pay for, and SE has the money it needed. It was a limited time offer.

Let it go.