AR Foundation support for wearables?

Hello, in the unity blog post of Dec 18, 2018, it says “In 2019 we are going to expand platform support beyond handheld AR to include wearable AR devices as well.” ( https://blogs.unity3d.com/2018/12/18/unitys-handheld-ar-ecosystem-ar-foundation-arcore-and-arkit/ ). What is the status of this?
Is it possible to participate in preview development? (even pre-alpha is ok ).

Thanks,
Jonathan