I think 7Artisans is going to be the next Chinese lens manufacturer to join the L-Mount Alliance. The company already has several L-mount lenses. Here are the latest details of their upcoming AF 85mm f/1.8 lens for L-mount (previously reported here):
SIRUI recently joined the L-Mount Alliance, and Leica publicly commented that they are looking for new participants. Viltrox is also currently negotiating for L-mount licensing: