On the League of Legends forums, designer director Andrei “Meddler” van Roon answered a player question about what champions Riot were considering with visual and gameplay reworks.
Van Roon responded with a concise list, including Amumu, Dr. Mungo, Corki, Fiddlesticks, Mordekaiser, Nocturne, Rammus, Pantheon and Volibear. He notes that this could change, though. He also notes in another comment that Jax could receive a small-scale VGU, similar to what Ezreal is going to get if the Prodigal Explorer’s goes well.
It’s important to note that this isn’t an official list of reworks to come, but just champions that Riot is looking at for the future. We do know that Ezreal, Kayle and Morgana are up for the next handful of reworks, with Kayle and Morgana’s not coming until 2019. That being said, it’ll be a long while before any of these champions will be reworked.
We more than likely won’t be seeing any further confirmation on who’s getting reworked until the next Champion Roadmap, which is due in early 2019.