Ethereal Hag Covens

[beaumontsebos]

Say that there is a hag coven and one is a night hag.

If the night hag becomes ethereal, but stays within 30 feet of the other hags, does the coven still gain the benefit of shared spellcasting?

 

[Quickleaf]

I'd say yes, because of how with other monsters with Etherealness (e.g. ghosts & phase spiders), it's apparent you're still intended to track the monster's location during combat even while it's on the Ethereal.