First time writing a post to you so hey what's up? And congrats to you and others who worked on the project skins.
But my question is will we be seeing anymore visual updates before the end of the year? I'm talkind like Maokai and Kass level. I think there are a couple of champs who could use a few touch ups to bring them up to date. e.g. 
and 
Hello!
I'm a part of skins team, which works on creating new skins content, as opposed to updated older content. Champion Update handles those kinds of things!
In regards to VUs, we have an ongoing list with the next updates in line. Taric is also being worked on, but he hasn't been added to this list. Should be updated soon since the Juggernauts are out now - keep an eye out!
Unfortunately, I don't have any information about updates for the champions you've listed. Sorry. :c
In case you wonder, I asked IronStylus, during his stream, about upcoming VUs- He basically said that right now, all VUs in development will come with Gameplay Updates, because a Gameplay Update (like Fiora's) is an opportunity for Visual tweaks and touchups.
Also:
-Nunu has a model that Josh Singh (Riot GrumpyMonkey) had done in his free time back in 2013, but not much came out of it. The team agrees that he could use a Visual Update, but currently, they are not working on him.
-Rumble got some really nice VFX updates and his Texture Rebalance really improved his look, but there's no VU of some sorts in development for him.
-Malphite should look as awesome as his new splash, the Texture Rebalance helped him, but he's currently not being worked on.
-Udyr needs to be figured out (thematically) first. He needs to have a more cohesive look that will tie him to where he's from. His animations are clunky and his model is old, but the Texture Rebalance did help him a little. Nothing in the works for him in terms of Champion Updates, right now.
-_-
P.S- This obviously doesn't mean that we're never going to see 'standalone VUs' anymore. It's just that right now, with all the gameplay updates that are needed to be done, they (the gameplay updates) serve as great opportunities for Visual touches (whether they are big or small).
