I was just wondering about all the champions that don't deliver (IN MY OPINION) on there champion design like: 
And on a much more personal note; 
Edit: And I mean to say minor kit reworks to match aesthetic and splash updates (Not in champs like Kindred and Rek tho)
Rek'Sai already got such an update like Xin Zhao. And in general, it seems that Aatrox was stopping the process.
Aatrox was supposed to be a gameplay update, just like Xin Zhao and Rek'Sai. But it turned out way larger (and they decided to update his visuals, too). So the team doing these updates is busy with him and can't work on other stuff.
They will probably continue doing these when Aatrox' rework is released.
Splash art updates are mostly focused on VGUs and since we'll get more of these this year,they don't have much time to update the splash arts of many other champs.
And like Satomikun said,their gameplayrework team has most likely their hands full with Aatrox,who will receive a major overhaul to his kit.
comes to mind
Zilean Rek'sai already had a Xin Zhao scale rework. Do your research.
And also, champions lie Xin Zhao, Jax, Zilean, and other older ones look like shit. They need full scale work to look modern, not minor kit work that will push them out further and further until they're so desperately ugly it hurts. Cho'Gath is in this scenario, as evidenced by the fact that they keep releasing skins for him despite how heinously ugly his model is.
