That cover the basics like city, forest, desert, mountains?
unfortunately not
Maybe not exactly what you’re asking, but Ultra Dynamic Sky was recently submitted for review.
We’ve gotten surprisingly few skyboxes. I have had a couple submissions in the past that were close but not quite at the quality bar we require. The main issues I’ve seen with skybox submissions are a) they’ve had foreground elements such as trees, which is incorrect and b) lack of color and contrast balance, which makes them stand out in a bad way. A skybox pack would be really useful if someone were to step up and submit one. 
If when I need some it gets to the point where I need to make my own, maybe I’ll submit them then =)