The League of Legends champion roadmap has teased some of the upcoming changes to Udyr in its most recent edition. Riot had previously let us know that Udyr would be receiving a VGU or visual gameplay update, but its release date has not yet been confirmed.
A VGU is similar to a rework but not completely. VGU's change a champion's look, movement, and attack animation along with its splash art. They do not change a champion's abilities or strength. Fans have complained for a while about Udyr's ancient look, especially after he received the game's second ever ultimate skin.
League of Legends Udyr Rework Teased in Champion Roadmap
Riot has noted that they plan on releasing a blog early next year with in-depth information about Udyr's VGU. Until then, we know that Riot has been targeting a couple of areas so far. The first one is his antlers, which are being designed to look prominent but small.
They have also decided to make each of his stances associated with a Freljordian demigod in order to connect him closer to Runeterra, based off positive feedback. "We’ve decided to lock in this direction, and we can’t wait to talk to you more about it in the next blog."