There have been rumors of the Cavs looking at trading into the lottery. They were linked to Barnes last year.
I don’t love Barnes by any means. He's not a good defender at this point, but he would add a front court player that can shoot the ball and is more playable than Niang. There’s also a decent possibility the Kings lose Monk in FA.
LeVert is a Monk replacement and gets the Kings out of the last year of Barnes’ deal.
The Cavs looked at Barnes last year. He’d add some shooting and maybe let Dean play more SF.
Probably a trade more likely to happen if the draft was after FA and they knew the situation with Monk, but I could potentially see them doing something like this even if Monk was back.