yasuo and zed are exhaustables. They can't do anything when exhausted by a normal player, imagine how little they can do when frame-perfectly exhausted by an experiences player who performs 300 actions-per-minute.
Lee is strangely balanced, which is to say he's deadly in the right hands, and not deadly in bad hands. People refuse to use him because his best jungle item isn't late game material.
Rek'sai gives as much control while being significantly less fragile. She's way too valuable now that teleports are nerfed. Chiefly, we're seeing her as one of two junglers in every single professional game right now.
Where's the goat lady go? If we're not even seeing Kindred, we've got something going on in the jungle. My guess is they want to see more of her. Or anybody else really.
EDIT: I forgot about Graves, we might see tons and tons of Graves. He's too good at jungle, he's my vote for the next prevalent jungler