Yeah, and there’s the mischievous aspect of Yoda coming through as he would know that a scary nearby cave would be a good lesson for Luke.
I wish this explanation worked as well for The Last Jedi. For that to work Rey would need to be subconsciously visualizing this darkness as within the cave beneath the island, though maybe the cave actually does have a Dark Side aspect in this case since it’s part of a legitimately ancient Jedi site. Eh, it’s not as concerning to me.