Shadow support for KHR_lights_punctual ?

Wondering if GLTF Lights can support shadows in ThreeJS? The lights work perfectly but there's no shadows and I'm having a hard time finding any documentation surrounding this besides this post. https://github.com/takahirox/KHR_lights_shadows

Start by reviewing the KHR_lights_punctual context in the issue and the linked KHR_lights_shadows proposal. Determine whether shadow support belongs in the glTF specification and what concrete behavior or documentation would define completion.

Written by the indexing model from the issue text.