>>40918557With the lack of new Ground-types, I could easily see it being one. I've also seen some people guess Rock/Ghost, which isn't completely out there, though I suppose it doesn't really have any super obvious ghostly features (Rock/Ghost evolution would have been nice, though.)
I think in the end it just might be pure Rock since they do like their monotypes in Galar, even though giving some of them secondary types would have done a lot to diversify the new guys if they're gonna insist on small generations.