The Leica Meet was founded by a group of photographers who shoot Leica. It was the sole purpose for meeting... to share their Leica experience and their love of the red dot.
So to stay true to this founding principle, the only qualifying rule of membership is shooting a Leica M, X, S, Q, T, CL, SL or any film Leica. Lenses are up to you.
If you shoot Leica and love your photography your'e more than welcome!